When introducing Zhao Zhouqiao (2) and (3) in China Stone Arch Bridge, why don't you explain the characteristics in descending order?

From big to small, Zhao Zhouqiao is not only unique in design, but also excellent in construction technology, with many ideas:

(1) The bridge site selection is reasonable and the bridge foundation is stable. According to his rich practical experience for many years, after careful exploration and comparison, Li Chun chose a relatively flat place on both sides of the * * River to build the bridge. The stratum here is alluvial by rivers, and the surface of stratum is coarse sand layer washed by water, followed by fine stone, coarse stone, fine sand and clay layer. According to modern calculation, the stratum here can bear the pressure of 4.5 to 6.6 kilograms per square centimeter, while the ground pressure in Zhao Zhouqiao is 5 to 6 kilograms per square centimeter, which can meet the requirements of bridges. After the bridge site is selected, the foundation and abutment are built on it. So far, the bridge foundation has only sunk 5 cm, indicating that the stratum here is very suitable for bridge construction.

(2) The masonry method in Zhao Zhouqiao is novel and convenient for construction and maintenance. Li Chun used local materials and selected hard blue-gray sandstone produced in nearby counties as the stone for building the bridge. In the stone arch laying method, the longitudinal (along the bridge direction) laying method is adopted, that is, the whole bridge is composed of 28 independent arch pieces side by side along the width direction, and the arch thickness is 1. Ozone meter. Each coupon is operated independently, and it is quite flexible. After each coupon is completely closed, it becomes an independent spell. This masonry method has many advantages, it can not only save the wood used for "scaffolding", but also facilitate movement; At the same time, it is beneficial to the maintenance of the bridge. If the stone of the arch coupon is damaged, it is only necessary to embed new stone and repair it locally, without adjusting the whole bridge.

(3) Many strict measures have been taken to keep the bridge stable. Li Chun adopted a series of technical measures to strengthen the horizontal connection between the arches, making the 28 arches form a tight and solid organic whole. L) Each arch piece adopts the method of "dividing points" slightly, so that each arch piece leans inward and leans against each other, so as to enhance its lateral connection and prevent the arch stone from dumping outward; In the width of the bridge, a small number of "demarcation points" are also adopted, that is, the width is gradually reduced from the two ends of the bridge to the top of the bridge, from the widest 9.6 meters to 9 meters, so as to strengthen the stability of the bridge. 2) Five tie bars are evenly arranged on the main ticket along the bridge width direction, passing through 28 arch tickets, and each tie bar has a semicircular head exposed outside the stone at both ends, so as to clamp the 28 arch tickets and enhance their transverse connection. There is an iron tie rod on each of the four small arches, which plays the same role. 3) Cover several arch stones near the outside and small arches at both ends with a layer of arch stones to protect the arch stones; There are six hook stones on both sides of the arch protector to hook the main arch stone to make it firmly connected. 4) In order to make the adjacent arch stones stick together closely, the "waist iron" which plays a connecting role is inserted between the adjacent arch stones on both sides of the outer connecting piece, and the adjacent stones between the connecting pieces are also inserted into the "waist iron" on the arch back to chain the arch stones. Moreover, the side of each arch stone is chiseled with fine twill to increase friction and strengthen the lateral connection of each coupon. These measures make the whole bridge become a close whole and enhance the stability and reliability of the whole bridge.

(4) The abutment of Zhao Zhouqiao is unique. Abutment is the foundation of the whole bridge, and it must be able to bear the huge horizontal thrust and vertical pressure of the main arch ring (bridge main body) axial force decomposition. The abutment in Zhao Zhouqiao has the following characteristics: l) the arch foot is low: the arch foot is only about half a meter below the river bed; 2) Shallow bridge foundation: the bridge foundation surface is about the arch foot1.7m; 3) Short abutment: From top to bottom, the abutment with a length of 5 meters, a width of 6.7 meters and a height of 9.6 meters is constructed with gradually slightly thickened stone strips. This is an economical, simple and practical abutment. In order to ensure the reliability of abutment, Li Chun has taken many corresponding foundation reinforcement measures. In order to reduce the vertical displacement of the abutment (that is, the subsidence caused by the vertical pressure of the bridge main body), Li Chun adopted the measures of driving many wooden stakes beside the abutment to strengthen the foundation of the abutment; This method is also often used in today's factory and bridge construction. In order to reduce the horizontal movement of the abutment (that is, the abutment moves backward due to the horizontal thrust of the bridge main body), Li Chun adopted the method of extending the back seat of the abutment to offset the horizontal thrust. In order to protect the abutment and abutment, Li Chun also set up a diamond-shaped wall along the river, which on the one hand can prevent the water from scouring, and on the other hand, the diamond-shaped wall is integrated with the abutment and abutment, thus increasing the stability of abutment. The above measures ensure that the bridge has a solid abutment and improve the stability of the bridge.

Lugou Bridge is also called Lugou Bridge. On Yongding River, Lugouqiao Town, Fengtai District. Founded in the Jin Dynasty, it has a history of nearly 865,438+00 years and is the oldest stone arch bridge in Beijing. Yongding River was originally named Lugou River, and the bridge was also named after Lugou.

Lugou Bridge is designed according to the characteristics of Yongding River. The bridge body is all made of white stone, with a total length of 2 1-2.2 meters and an approach bridge at both ends of 266.5 meters. Bridge arch 1 1, 7.5m wide, 279 railings, carved stone railings on the left side 140, carved stone railings on the right side 14 1, the column height1.4m, and the heads are all carved with crouching tiger and stone lions. The whole bridge structure, piers and arches are fastened with waist iron to strengthen the connection between stones. The pier is boat-shaped, and the water facing the pier is built into diversion tips, and triangular iron columns are placed on each tip to resist spring ice and floods.

Lugou Bridge is also famous for its exquisite stone carving art. There are 28 1 sentry boxes on both sides of the bridge, with lotus seats engraved on the stigma and lotus leaf piers under the seats. There are 279 fences embedded in the middle of the observation column, and patterns such as Aquarius and moire are engraved on the inside of the fence and the outside of the bridge deck. The number of stone lions carved on each sentry post in the four periods of Jin, Yuan, Ming and Qing varies, and most of them are original objects of Ming and Qing Dynasties, few in Jin Dynasty and few in Yuan Dynasty. These stone lions crouch and lie in different postures, which are lifelike and varied, and are the fine works of stone carving art in Lugouqiao. Because there are too many stone lions on the bridge, people can't count them, so there is a two-part allegorical saying in Beijing that there are countless stone lions on Lugou Bridge. 196 1 year, cultural relics workers counted 485 stone lions according to their numbers. 1984 checked again and found that there were as many as 489 stone lions on the bridge.

Lugou Bridge was built in the 25th year of Jin Dading (1 189) and rebuilt in the 9th year of Ming Dynasty (1444). It was destroyed by floods during the reign of Kangxi in the Qing Dynasty and rebuilt in the thirty-seventh year of Kangxi (1698). There is a white marble tablet in the pavilion in the east of Qiaodong, titled "Lugou Xiaoyue", which is one of the "Eight Scenes of Yanjing". Italian traveler Kyle Poirot praised "it is the best and unique bridge in the world" in his travel notes.

1On July 7th, 937, the first anti-Japanese cannon shot sounded at the bank of Lugou Bridge, and the national liberation war began here. Lugouqiao Historical Materials Exhibition Hall was officially opened at Qiaotou on July 7th, 198 1. 1987 "China People's War of Resistance against Japanese Aggression Memorial Hall" was officially completed. On the steps of the memorial hall, there is an artistic sculpture 4 meters high-the lion wakes up, which symbolizes the heroic and unyielding national spirit of the Chinese nation.

Respondent: ctd cy 234- apprentice wizard level 3 1 1-27 20:59.

Teaching objectives

Moral education: Understand the long history and outstanding achievements of Chinese stone arch bridge, know the wisdom of ancient working people, inspire students' feelings of loving the motherland, devote themselves to scientific aspirations and rigorous and pragmatic spirit.

Knowledge points: accumulate words such as "majestic, broken, simple, respectful, vivid and ingenious" and master the pronunciation and meaning; Understand the great achievements of bridge construction in China and master the characteristics of stone arch bridges.

Ability point: Understand the explanatory object, grasp the characteristics of the object, perceive the meaning of the text as a whole, and cultivate the ability to read the explanatory text initially; Grasp the order of interpretation, explore the author's interpretation skills, understand the author's way of thinking about things, and cultivate students' generalization ability; Try to figure out the language and grasp the characteristics of plain, accurate and thorough explanation language; Understand the differences in writing purpose and language use between expository and narrative.

Teaching focus

1. Guide students to master the characteristics of stone arch bridges and the methods to explain things by mastering the characteristics.

2. Taste the accuracy and rigor of language.

Teaching difficulties

This paper focuses on Zhao Zhouqiao and Lugou Bridge to explain the Chinese stone arch bridge, understand the author's interpretation order, and explore the author's interpretation skills.

teaching method

1. Students' independent reading is combined with teachers' guidance. Let students read and think by themselves, with the help of teachers' guidance, turn boring into vividness, turn dead silence into agility, and improve the classroom teaching efficiency of expository writing.

2. Discussion method. Discussion method is the embodiment of democratic thought in classroom teaching, which is helpful to stimulate students to actively participate in teaching and cultivate their ability of comment and debate. Through discussion, students can cooperate with each other, dare to question and constantly improve their thinking ability, which is conducive to the development of students' intelligence.

training/teaching aid

Multimedia and written materials.

Teaching assumption

We should grasp the characteristics of the things to be explained in teaching. This is the soul of expository writing. Only by grasping the characteristics and making it clear can we make things clear. Choose an explanation method to explain the characteristics of things. In this paper, the most prominent explanation method is to quote typical cases, which occupy a large proportion in the text and play a significant role in interpretation, and also help students understand the essential characteristics of explanatory texts. Therefore, it is necessary to put case analysis in an important position and make clear the relationship between cases and the essential characteristics of things.

Learning expository texts can be done by guiding students to analyze comparative languages, or by combining talking about other interpretation methods (such as analogy) and learning grammar knowledge (analyzing sentence components).

Be careful not to talk about bridge knowledge.

Arrange two classes.

Teaching step

first kind

First, the introduction of new courses.

The bridge is an enlarged bench-Mao Yisheng, a bridge expert, explains the "bridge" in such a funny way. Today, we will learn the Chinese Stone Arch Bridge written by Mr. Mao Yisheng, understand the characteristics of the stone arch bridge with a long history, beautiful shape and solid structure, and feel the diligence and wisdom of our working people.

Second, check the preview and solve the problem.

1. Athena Chu: steep slope of arc arch bridge and symmetrical pier Li Daoyuan of Harmonious Drinking Stream.

2. Explain the meaning and meaning of words: vivid, harmonious, symmetrical, simple and ingenious.

The above two items can be displayed by multimedia or projection.

3. discuss the topic.

(1) Analyze the phrase structure of "Chinese stone arch bridge".

Noun-based phrases

The Central Word-"Bridge"

Several attributes-"China", "Stone" and "Arch".

Together, it is the "China Stone Arch Bridge".

(2) Interpretation of the word "arch".

What shape is the arch? Please combine the words with the word "arch".

-"Arch", the original meaning is to put your hands together and raise them to show respect, such as "handing over", which can be combined into words: arch hug, arch, bridge arch, bucket arch, etc. And the meaning is extended to "around" and "arc". The same is true of the "arch bridge".

4. Problem solving: The text we want to learn is a scientific description of bridges written by Mao Yisheng, a famous bridge expert.

Excuse me: What kinds of bridges are there?

-First, the classification criteria should be clear. According to the country, there are China and foreign countries; According to building materials, Shi Cun has wood and steel; According to the shape, there are flat and arched. This passage clearly defines the "bridge" with three attributes. So, what are the characteristics of this "Chinese stone arch bridge"? How does the author introduce this function to everyone? These are two important issues that we should understand when studying this text.

Third, click Read.

(A) the characteristics of Chinese stone arch bridge.

In order to make things clear, the explanatory text pays special attention to the order of explanation, which we learned when we studied the language of nature and other texts in senior one. Now students read quickly, find out each paragraph in three minutes, and mark the textbook with a pen when reading.

Teachers are on the job. Blackboard writing:

Stone arch bridge: (1-2) Chinese stone arch bridge: ancient condition (3-9) Chinese stone arch bridge: contemporary development (10)

1. Characteristics of stone arch bridge.

Ask one student to read paragraphs 1 and 2, and the other students will find words to explain the characteristics of the stone arch bridge.

Teachers are on the job. Blackboard writing:

Appear ahead of time

Graceful form

Structure-solid

How does the author explain these characteristics? (Students can be organized to answer or teachers can point out, depending on the time)

Myths compare rainbows to bridges, while poets compare bridges to rainbows. The contrast between the bridge and the rainbow shows not only the shape of the bridge but also its beauty. Metaphor is to illustrate, with the meaning of praising beauty, but the language is concise and appropriate.

"It can cross the river for decades, hundreds or even thousands of years" not only shows that the stone arch bridge appeared earlier, but also shows that its structure is firm.

Paragraph 1 shows that the stone arch bridge is beautiful in form, and paragraph 2 shows that the stone arch bridge is firm in structure, which reflects the writing order from the outside to the inside. "Not only that ... but also ..." The progressive relationship accurately embodies and emphasizes this point.

2. Characteristics of stone arch bridges in China.

The third paragraph begins to explain the Chinese stone arch bridge. Draw the characteristics of the Chinese stone arch bridge, and see if the general characteristics of the stone arch bridge mentioned in the last two paragraphs are also available in China. What are the unique features of the Chinese stone arch bridge?

Teachers are on the job. Blackboard writing:

A long history-a long history

Almost everywhere ―― numerous and extensive.

Different sizes and forms, many of which are amazing masterpieces-diverse and outstanding.

In terms of time, the stone arch bridge in China occupies a leading position in the history of bridges in the world. According to: (1) "long history" emphasizes early time; ② The "passenger bridge" may be the earliest recorded stone arch bridge. What about form and structure? This passage affirms that many stone arch bridges in China are amazing masterpieces, which shows that our stone arch bridges are "amazing" bridges. In addition, there are many stone arch bridges in China, which are widely distributed, some grand and some small and colorful. It can be seen that our ancestors made outstanding contributions to mankind in this respect.

Zhao Zhouqiao and Lugouqiao are the representatives of this amazing masterpiece. Through the introduction of these two bridges, the author better explains the characteristics of Chinese stone arch bridges.

3. Zhao Zhouqiao, one of the masterpieces of stone arch bridge in China.

This article introduces Zhao Zhouqiao in the fourth and fifth paragraphs. Mark the relevant sentences in the reading to see what are the characteristics of Zhao Zhouqiao, what are the stone arch bridges and what are the unique and outstanding features of Zhao Zhouqiao?

Teachers are on the job. Blackboard writing:

Zhao Zhouqiao is a world-famous ancient stone arch bridge and one of the amazing masterpieces of Chinese stone arch bridges. It has the general characteristics of stone arch bridge. In the fourth paragraph, the article gives a general introduction to this point. "It has been more than 1,300 years" shows that it appeared early, "it has been used since it was created" and "it has maintained its original appearance", which shows its firmness and beauty. At the same time, Zhao Zhouqiao has its own unique features, which is really an amazing masterpiece.

The length and width data of the fifth section of the bridge show that it is amazingly magnificent. Then it points out that its design is scientific and its technology is ingenious, which is the reason why Zhao Zhouqiao is outstanding in general. The following four aspects to explain its scientific and ingenuity. What students should pay attention to is that each aspect not only introduces the characteristics, but also explains the principle of this design and construction. This is the characteristic of plain text: explaining things and their reasons.

(1) A "37.4m long" arch, the largest in the world at that time, how to ensure convenient transportation?

Designers in Zhao Zhouqiao broke away from convention and designed bridge opening into an arch. There is no steep slope on the bridge deck, so it is convenient to get up and down. It can be said that it is really smart.

(2) This kind of bridge is a single arch bridge, and a lot of stones are used, which will cause great pressure on the bridge foundations on both sides. What should I do?

—— The surge of the river in flood season will have a violent impact on the bridge. What should I do? The designer's creative design, adding arch to arch, not only kills two birds with one stone, but also receives beautiful miraculous effects, which is really ingenious.

The bridge is so long and wide, how can it be secured? How to facilitate construction?

-The designer is ingenious, assembling an arc bridge opening with 28 arch rings, which is really strange.

(4) In addition to the ingenious structure, Zhao Zhouqiao's figure is also symmetrical and beautiful, harmonious with the surrounding scenery, and its artistic value is immortal.

It is worth noting that the author quoted Zhang's previous explanation of the strange structure of the bridge and his later explanation of the beautiful form of the bridge. Finally, he pointed out that Zhao Zhouqiao is the crystallization of the wisdom and strength of the working people represented by Li Chun. Summarize first, then divide and summarize again, and introduce the characteristics of Zhao Zhouqiao clearly.

Fourth, class summary.

The uniqueness of Zhao Zhouqiao strongly illustrates the characteristics of Chinese stone arch bridges. Zhao Zhouqiao is a single arch stone bridge, located on the Chan River. Next, the article takes the multi-arch stone bridge Lugou Bridge on Yongding River as an example, which proves the characteristics of large number, wide distribution and various forms of stone arch bridges in China.

Verb (abbreviation for verb) assigns homework.

1. Thinking: What is the relationship between the unique characteristics of Zhao Zhouqiao and the characteristics of Chinese stone arch bridges?

2. Complete Exercise 1 and Exercise 2 (The Lugouqiao part is a preview, so don't fill in the form yet, but mark it on the text. )

3. Preview and think about three, four and five.

Second lesson

First of all, review the old and learn the new.

1. Talk about the relationship between the uniqueness of Zhao Zhouqiao and the characteristics of Chinese stone arch bridges.

2. Talk about the characteristics of Lugou Bridge.

Second, guide the new curriculum

1, another masterpiece of Chinese stone arch bridge-Lugou Bridge.

Lugou Bridge is another masterpiece of Chinese stone arch bridge. The students were invited to audition. Now let's discuss the similarities and differences between Lugou Bridge and Zhao Zhouqiao.

Location: On Yongding River, which is wider than Weihe River.

-time, later than Zhao Zhouqiao, but it has been more than 800 years, which is a long history.

This bridge is much longer and slightly narrower than Zhao Zhouqiao. The bridge deck is flatter. The biggest structural difference is that Lugou Bridge is a multi-arch stone bridge, which relies on stone piers to unite as a whole to resist floods.

-It's also very nice, especially the stone lions with various stigmas.

-Lugou Bridge enjoys a good reputation at home and abroad, and is a memorial site of War of Resistance against Japanese Aggression.

Induction, writing on the blackboard:

Last class, we summarized the characteristics of Chinese stone arch bridges. In addition to the general characteristics of stone arch bridges: early appearance, firm structure and beautiful shape, there are only more prominent characteristics such as long history, large number, wide distribution and outstanding diversity. Typical examples of Zhao Zhouqiao and Lugou Bridge have proved these characteristics well. Among them, the article fully introduces their outstanding points: ingenious, strange and exquisite, because this aspect can best explain the outstanding achievements of Chinese stone arch bridges in terms of solid structure and beautiful form. This text provides us with a good example of how to choose and use examples when explaining things.

2. The reasons for the brilliant achievements of China's stone arch bridge.

Read paragraph 9 by roll call, and other students will mark and summarize while listening. There are several reasons. What is this?

There are three reasons: first, the diligence and wisdom of the working people; Secondly, the design and construction have a fine tradition ("saving materials, skillful structure and high strength", with Zhao Zhouqiao and Lugou Bridge as outstanding representatives); Secondly, there are all kinds of stones used in buildings. The first of these three is the most important, because the hard work and wisdom of the people make it possible to use rich stones and carry forward fine traditions.

3. Modern development of stone arch bridges in China.

Read paragraph 10. Thinking: What examples are listed in this paragraph to illustrate the new development of stone arch bridge in China?

Changhong Bridge is the longest single-arch stone bridge in the world, with an arch length of112.5m, which is three times that of Zhao Zhouqiao. This double-curved arch bridge is the only one in the world, with a total length of more than 200,000 meters. The longest hole is 150 meters. This kind of reinforced concrete arch bridge inherits and develops the tradition of stone arch bridge.

This new development and achievement is attributed to a new reason: the socialist system is extremely superior.

4. The explanation language is plain, accurate and rigorous.

Discuss the exercises after class and the teacher will summarize them.

Taking Zhao Zhouqiao and Lugou Bridge as examples, this exposition clearly introduces the Chinese stone arch bridge, which is inseparable from its excellent use of exposition. There are four aspects worth learning from.

(1) language is plain and concise, and its description is moderate.

This passage belongs to the same style as the entries in Ci Hai, which only further explains the reasons for the structure of Lugou Bridge. This passage is also described, but it is very gentle. For example, 1 paragraph compares the bridge to a rainbow to illustrate the arc of the bridge, and praise is hidden in it.

It shows that the stone lions in Lugouqiao are described, reflecting their feelings, but they stopped moderately instead of indulging in words. There are only three sentences to say that Lugouqiao is the holy land of the Anti-Japanese War: one is to commemorate the significance, the other is to explain the time and nature of the war, and the other is to explain the leaders and results of the anti-aggression war, which is concise.

(2) Using the explanation method, the purpose is clear.

In order to explain things accurately and vividly, articles often use various methods of explanation. Students should pay attention to experience without using any explanation methods, in order to introduce relevant knowledge and explain the characteristics of things.

Quote an ancient book-"Zhang Shuo in the Tang Dynasty did something strange,' people know why'."

List the figures-"Zhao Zhouqiao is very majestic, with a total length of 50.82 meters, a width of 9.6 meters at both ends, a slight narrow middle and a width of 9 meters."

Metaphorically-"China poets like to compare the arch bridge to a rainbow, saying that the arch bridge is' lying rainbow' and' flying rainbow', and describing the water arch bridge as' Changhong lying wave'."

Describe it-"the whole bridge is symmetrical in structure and very harmonious with the surrounding scenery;" Even the stone railings on the bridge are beautifully carved. "

Explanation-"There is a stone pier between every two stone arches, which connects eleven stone arches into a whole. Because the arches are connected together, this kind of bridge is called' double arch stone bridge'. "

It is these plain, accurate and rigorous explanation languages that have achieved clear results.

(3) Carefully choose words and pay attention to discretion.

Some words are very clear, such as the listed time and data, and the restrictions on certain time and degree; Some words mean to estimate. Either way, there is only one purpose: accurate explanation; There is only one basis: it conforms to reality.

For example, in "Crossing the Bridge", the three attributives of "possibility" (indicating estimation), "record" (limiting) and "earliest" (definitely limiting the time after estimation and limiting) are used to make it clear. For another example, the interpretation of Zhao Zhouqiao uses two attributes: "it has been used since it was created" and "the oldest". The second attribute shows that Zhao Zhouqiao has a long history, but it is accurate only under the restriction of the first attribute. "Stone arch bridges are almost everywhere in China" and "ubiquitous" means "a large number and wide distribution", but only under the restriction of "almost" can it be true and accurate. Lugou Bridge "The length of each stone arch bridge is different" is the conclusion after textual research on the length of eleven stone arch bridges. Once a student asked Mao Yisheng about it, and Mao Yisheng wrote back and listed the lengths of eleven stone arches, all of which were really the same. A seemingly plain sentence reflects the accuracy and rigor of explaining the language. The requirements of descriptive language are particularly reflected in the use of attributes, adverbials and complements in this text, which students can pay attention to.

4. Pay attention to the order of words and phrases, and be cautious and reasonable.

Writing the form first is the intuitive impression given by the bridge and the perceptual knowledge. Strong structure is a further understanding of the bridge, that is, a rational understanding. Therefore, the relationship between them is progressive rather than parallel. "Not only that ... but also ..." embodies a reasonable order and cannot be deleted or reversed.

The small arch on the shoulder is the main feature initiated by Zhao Zhouqiao, which best illustrates Zhao Zhouqiao's originality and strangeness. Other arch bridges also have arch rings, which are secondary to the small arch on the shoulder.

First of all, Zhao Zhouqiao's appearance, design and architectural features are always described, and then described in detail at four points, giving a clear impression. For another example, to explain the reasons for the brilliant achievements of stone arch bridges in China, the words "first", "second" and "second" are used to describe them separately, from people to things, from primary to secondary, with reasonable order and clear labels.

Third, the class summary

On the basis of students' summary, the teacher concluded:

1. This paper introduces the characteristics of China's stone arch bridge, its brilliant achievements in history and the development after the founding of New China, and praises the intelligence and wisdom of our working people and the superiority of the socialist system.

2. Taking Zhao Zhouqiao and Lugou Bridge as examples, the characteristics of stone arch bridges in China are elaborated, the reasons are analyzed, and the development status is introduced.

3. This paper is excellent in the use of explanatory language: concise, plain, accurate and thorough. Language style is different from narration.

Fourth, homework

1. Please clarify the interpretation order of the words about Zhao Zhouqiao and Lugou Bridge.

2. According to the text and illustrations, draw a schematic diagram of Zhao Zhouqiao and mark the corresponding data.

3. Try to understand this language.

(1) The bridge opening of the stone arch bridge is curved, just like a rainbow. According to ancient mythology, the rainbow is a "bridge connecting heaven and earth" after rain, and you can go to heaven through the rainbow. Poets in our country like to compare the arch bridge to a rainbow ... (Can the bold words "stone arch bridge", "bridge" and "arch bridge" be replaced? Why? )

-Not interchangeable. Because the text introduces the "Chinese stone arch bridge", the first sentence closely follows the topic and uses the concept of "stone arch bridge". In ancient times, people could only understand the world in the form of myths, saying that "the rainbow after the rain is a bridge between the world and the sky", and here we can only take care of "myths" with "bridges". As for "comparing the arch bridge to a rainbow", it is closely related to the arc-shaped characteristics of the bridge holes of the "arch bridge".

② Stone arch bridge appeared earlier in the history of bridges in the world. Can you delete the word "comparison"? )

-The degree of "earlier" is lighter, so the expression is safer.

This kind of bridge is not only beautiful in appearance, but also firm in structure. (Can you delete "not only" and "and"? Can the order of "firm structure" and "beautiful form" be adjusted? )

-"Not only" and "and" cannot be deleted. If they are deleted, the relationship between them becomes parallel. It is in line with people's cognitive logic to talk about appearance first and then function. For bridges, in fact, the use value is far more important than the form, so the order of the two can not be adjusted.

(4) The "passenger bridge" mentioned in Shuijing Zhuan was built in about 282 AD, which may be the earliest stone arch bridge recorded. (Can bold words be removed? )

-"Probably" and "Possibility" both mean uncertainty, just speculation. "Well-documented" makes the basis of speech more reliable.

⑤ Stone arch bridges can be seen almost everywhere in China. (Can you delete "almost"? )

"Almost" emphasizes that stone arch bridges are widely distributed, but it does not rule out the possibility that there are no stone arch bridges in some places.

⑥ (Zhao Zhouqiao) The whole bridge has only one big arch, which is 37.4 meters long, and it was the longest stone bridge in the world at that time.

-"At that time" has a time limit, and "can be counted" has a degree limit. This is more in line with the actual situation.

⑦ A. Zhao Zhouqiao is very majestic, with a total length of 50.82 meters. Lugou Bridge is about 8 meters wide. What did you find? )

-Comparing the two sentences, we can find the author's rigorous scientific attitude. A Zhao Zhouqiao over 50 meters long can be accurate to 0.0 1 meter, which is an accurate explanation. "About" means that the width of Lugou Bridge is not exactly 8 meters, which shows the author's writing attitude of seeking truth from facts.

Students read sentences, think about experiences and communicate at the same table. Teacher's guidance: the language of explanatory writing has the characteristics of accuracy and rigor. Look at the above example, you can find this article: use numbers accurately; If there is no way to use accurate figures, use estimated figures; For the meaning of temporary uncertainty, express it in speculative language; Proper use of restrictive words makes the meaning expressed more accurate. Therefore, the most important thing for us to learn expository writing is to grasp the word "quasi".

Students find accurate and rigorous examples to communicate in class.

● Activities and surveys

1, a small test

(1) We live in a water town in the south of the Yangtze River, and there are bridges everywhere. Some of the bridges you have walked over may be just stepping stones and single-plank bridges, or they may be tall and strong reinforced concrete bridges, which may have been built for some years or may be newly built. In any case, they have their own functions and characteristics in structure and building materials. Please observe them carefully, understand and collect information about their construction, write an introductory text of about 500 words, and introduce a familiar bridge in a certain order.

Tip: write an explanatory article. Don't waste too much ink on the story about the bridge and the emotional expression of the bridge. Language should be concise and accurate.

(2) Faced with overpasses extending in all directions, drivers and pedestrians are at a loss. Try to write a "driver's guide" essay of about 400 words, which is about an overpass in my hometown city.

(3) Please write two articles with different genres on the topic of "Xx Bridge in my hometown": one is narrative and the other is explanatory.

Step 2 carry forward the past and forge ahead

(1) Imagine the future bridge, draw it, communicate in groups first, and then select a representative from each group to report to the class.

Tip: The idea of future bridges is based on the understanding of the shortcomings and defects of current bridges, so we can discuss what needs to be improved in various types and uses of bridges first, and then imagine what the future bridges will look like.

(2) Collect the information of famous bridges at home and abroad after class, and then classify them from different angles (such as structure, function and building materials). ), and select some distinctive bridges to create small files for them.