Science test papers and answers for seventh grade students

Self-assessment unit exercises for seventh-grade students in "Science" in the second semester of the 2006 school year

Final examination paper (questionnaire)

1. Multiple choice questions: (each Question 3 points, ***75 points)

1. As shown in the picture, which sense does a blind person use when "reading" Braille--------------------------------- -------------( )

A. Vision

B. Touch

C. Hearing

D. Sense of smell

2. Xiao Ming took a car to Jinhua. In order to prevent the sun from entering, the curtains were closed in the car. At this time, he found that an empty can that had been motionless on the ground rolled forward. At this time, the car

A. Accelerate and drive forward B. Move at a constant speed C. Decelerate and drive forward D. Stationary

3. Use a pry bar to pry a stone, as shown in the picture, it is easier to hold the end of the pry bar than the middle of the pry bar; this process shows that the effect of force is related to which of the following factors------ -------------------------------------------------- -----------( )

A. The magnitude of the force B. The direction of the force C. The point of action of the force D. The force exerting object

No. 3 Question 4

4. Xiao Ming and Xiao Zhong used harpoons to catch fish together. On the river bank, they saw a small fish (as shown in the picture). In which direction do you think they should insert the harpoon? -------------------------------------------------- --------------------------------------------------( )

A, AB B, AC C, AD D, none of them are correct

5. Assuming that the friction between all objects disappears, which of the following phenomena cannot occur------------------------------( )

A. A car stationary on a level road cannot move

B. We cannot write with a pen in hand

C. People standing on the ground have no pressure on the ground

D. You can push the train with one finger

6. Just after finishing the section "Balance of Two Forces", the students became very interested in whether the natural science textbooks placed on the horizontal table were affected by balancing forces.

Four students in the class also argued about this. Do you think their views are correct ----- ( )

A. A: The gravity of the book and the support of the book on the table The force is a pair of balanced forces

B, B: The support force of the tabletop on the book and the pressure of the book on the tabletop are a pair of balanced forces

C, C: The sum of the gravity of the book The pressure of the book on the tabletop is a pair of balancing forces D. D: The book is not subject to a balancing force

7. The picture on the right is a contour topographic map of a certain place. The place where the contour lines overlap in the picture represents a --------------------------- ----------( )

A. Mountain top B. Cliff C. Ridge D. Valley

8. Observed from a plane mirror, a sign number is "011-018", then the actual number of the sign is -------------------------- ( )

A. 110-018 B. 810-110 C. 018-110 D. 011-810

9. In bonsai making, in order for the plant to flourish, the top of the plant in the pot is often cut off. This is to allow which part to develop better

A, top bud B, side bud C , root D, flower

10. During an outdoor activity, if an old man next to you suddenly faints and his breathing and pulse have stopped, the measures and reasons you should take at this time are---------------- -------------------------------------------------- --------------------------( )

A. The old man's heart has stopped beating and he is dead. He does not need medical treatment.

B. The old man has stopped breathing and is dead. He does not need medical treatment.

C. The old man has no pulse and has stopped breathing. He is dead and does not need help.

D. Although the pulse and breathing have stopped, he cannot be judged to be dead and should call for help immediately.

11. The first cell of the next generation of plants is------------------------------------------------ --------------------------------( )

A. Fertilized egg B. Sperm C. Ovule D, egg

12. As shown in the figure on the right, the relationship between the distance and time of an object during linear motion. A, B, C, and D are four equal time intervals. In which time interval does the object have the highest average speed? ---------------------------- ( )

A. A

B. B

C. C

D. Ding

13. Spring is warm and flowers are blooming, and little bees are flying around among the flowers, their feet covered with thick pollen.

The behavior of bees helps plants ( )

A. Fertilization B. Seed germination C. Pollination D. Flowering

14. Which of the following are not characteristics of pubertal development------------------------------------------------ --------------------------( )

A. The first characteristic appears B. Brain structure and function develop rapidly

C. Men begin to have nocturnal emissions D. Women begin to have menstruation

15. The larger number of seeds in apples is related to which of the following structures--------------------------------------------- -------------( )

A, receptacle B, style C, ovule D, ovary

16. In order to study the effect of water on soybean germination, classmate Xiaoli planted soybean seeds in two identical flower pots and designed the following experiment.

The mistake that should be corrected in this experimental design is the two flower pots--------------------------------------------- -----( )

Flower pot light conditions, temperature and water

A is 20℃ in a sunny place, which is sufficient

B is in a dark place and is 20℃, which is not enough

A. Both should be placed in a sunny place. B. Both should be watered with sufficient water.

C. The temperature should be 0℃. D. Both should be watered without water.

17． The convex lens that should be drawn in the box below is: ---------------------------------------------- ----------------------------------( )

18. When using reading glasses lenses for imaging experiments, it cannot be done--------------------------------------------- ------------------( )

A. Magnified real image B. Magnified virtual image

C. Inverted real image D , Inverted virtual image

19. Among the structures of pea seeds that can develop into pea seedlings---------------------------------- ---------------------( )

A, endosperm B, embryo C, germ D, cotyledon

20 ． An object is placed on an incline. The correct schematic diagram of the gravity on the object is---------------------------------( )

21. If at 12:00 noon on the summer solstice, Xiaoli is in Beijing's Tiananmen Square and Xiaoxin is in Jinhua People's Square and measure the shadow of a one-meter-long bamboo pole at the same time, the most likely result is ---------- -------------------------------------------------- ----( )

A. The shadows of the poles in the two places are the same length B. The one in Jinhua is long and the one in Beijing is short

C. The one in Beijing is long and the one in Jinhua is short D. Not necessarily

22． Xiao Ming's hometown happens to be on the Tropic of Cancer, and his hometown can be observed throughout the year--------------------------------- ( )

A. One direct sun exposure B. Two direct sun exposures

C. Direct sun exposure every day D. No direct sun exposure

twenty three. The phenomenon caused by the rotation of the earth is--------------------------------------------- --------------------------( )

A. The earth is divided into day and night hemispheres B. On the earth There is an alternation between day and night

C. The twilight line moves from west to east on the surface of the earth. D. The phenomenon of polar day and polar night appears on the earth

24. We usually refer to areas with "large altitude and small relative height" as ---------------------------------- ---( )

A. Mountain B. Plateau C. Plain D. Hills

25. Xiao Ming’s birthday is September 9th. He wants to celebrate two birthdays in a row within one year. Which of the following methods can achieve this?

------( )

A. After passing September 9th in East District 12, then cross the date line to West District 12

B. Pass in West District 12 After September 9th, cross the date line to East District 12

C. After September 8th in West District 12, cross the date line to East District 12

D , after passing September 8th in the East 12th District, then cross the date line to the West 12th District

2. Fill in the blanks: (2 points for each blank, ***30 points)

26. During a celebration, a helium balloon carrying a slogan stood vertically in the air. If the mass of the slogan was 3kg, the pulling force on the slogan was N. (g=10N/kg)

27. During a field trip, a classmate found in front of a cliff that the rock layers on the cliff were very obvious (as shown in the picture on the right). This was because the rocks in that place were deformed under the action of internal forces.

It’s done. (Fill in “bend” or “break”)

28. Such an ornamental plant is now available on the market: cut a section of it and insert it into the water. In a few days, roots will grow, and then it will be transplanted into the soil to become a new plant. This method of reproduction is called , and it belongs to reproduction.

29. When a beam of light slants from the air to the water surface, the light beam may be reflected or reflected. After entering the water, the propagation speed of the light will (fill in "unchanged", "become smaller" or "become larger").

30. As shown in the picture on the right, such an experiment is done in a vacuum. A beam of light shoots from point S to the mirror and passes through point A after reflection. When it is reflected and passes through point A, its speed is 3×108 meters/second. (Fill in "greater than",

"equal to" or "less than").

31． A small wooden block is floating on the water at rest. The gravity of the small wooden block is 3 Newtons, and the buoyancy force of the water on it is (fill in "greater than", "less than" or "equal to") 3 Newtons.

32. A wooden box weighing 5000N placed on the level ground will move in a straight line at a constant speed when it is pushed horizontally to the right by a force of 100N. The friction force on the wooden box is N. After placing a few logs under the wooden box, it will still move horizontally at a constant speed. Push to the right, the friction force on the wooden box at this time (fill in "increase", "decrease" or "unchanged"), the resultant force on the wooden box in the horizontal direction is N.

33． What changes will occur in the appearance of boys and girls during adolescence compared with childhood? (Please give two examples each)

Boys:

Girls:

34. A feather falls from the air in a straight line at a constant speed, and the resistance it experiences is 0.0098 Newtons. The mass of this feather is grams.

35. In front of a high wall, Xiao Zhao clapped his hands, and immediately he heard an echo. If he is 170 meters away from the high wall and the speed of sound is 340 meters/second, he will hear an echo seconds after clapping.

3. Analysis and explanation questions (2 points each, ***30 points)

36. Answer the following questions based on the picture on the right.

(1) The latitude line where the sun shines directly is called .

(2) The solar term of this day is .

(3) The season in the Northern Hemisphere is .

The phenomenon of day and night length changes

is .

37. The following is a paragraph from an imaginary essay written by a classmate. Based on the knowledge you have learned, please write down three errors in the essay:

...On December 22, I was reviewing my homework, and suddenly All friction and air resistance disappeared. With a tap of my toes, I flew up. Flying and flying, I arrived over the North Pole and saw some cute polar bears playing in the snow under the sun. Flying further up, I looked down and found that the earth rotates clockwise from east to west...

The errors are: (1)

(2)

(3)

38. Liangliang's brother was serving in the military in Xinjiang. One night at eight o'clock in the evening, Liangliang had finished reviewing his homework in Jinhua and was about to go to bed. At this time, his brother called from Xinjiang: "...it's only a little after six o'clock now, why are you so early?" Are you sleeping? We just finished eating!" Liangliang was confused: It was obviously after eight o'clock, why did my brother say it was after six o'clock? Please help him explain the reason: . (4 points)

39. "A hemp house, a red tent, and a fat white man living inside." This is a riddle about peanuts. Please answer according to the picture below:

(1) 2 in the picture will develop into it in the future;

(2) People’s practical peanut oil mainly comes from (fill in the serial number) in the picture;

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(3) 1, 2, 3, and 4 in the picture together are the "white fat man" in the riddle, which is called the larvae of a new plant.

40. In the picture below, A, B, and C are three contour topographic maps, and D, E, and F are actual topographic maps (the shaded areas represent mountains or highlands). Please use short lines to match them one by one:

4. Experiment and exploration: (***15 points)

41. As shown in the pictures A and B on the right, the two inclined planes are the same, the materials on the planes are wooden boards and cotton cloth respectively, and a small car is Slide freely down the two slopes at the same height, and then stop at the position as shown in the picture. Based on the above experimental phenomena, please answer:

①The car stops after moving for a certain distance on the plane

The reason is: . (2 points)

②The purpose of this experiment is

. (2 points)

③In the above experiment, if the plane is made of ideally smooth material,

when the car slides down the slope, the movement of the car on the plane will be

Yes. (2 points)

42. Objects fall from the sky fast or slowly. Some people say that the speed of a falling object is related to the mass of the object. Objects with a large mass fall faster, and objects with a small mass fall slowly.

What other factors do you think may be related to the speed of an object falling? (Write at least two) (2 points)

Next, let’s study the relationship between the falling speed of an object and the mass of the object:

(1) Ask a question: the falling speed of an object and the mass of the object Related?

(2) Establish a hypothesis: Objects with large masses fall faster than objects with small masses

(3) Experimental verification and data collection: (Xiao Ming and Xiao Zhong conducted experiments separately )

Xiao Ming picked up an object in each of his left and right hands and let it fall together on the roof...

(a) The variables that should be kept the same in the experiment are: (2 points)

The different variables are: (1 point)

(b) There are two methods to compare the speed of object movement. The method used in this experiment is:

(2 points)

(4) Analyze the data and draw conclusions: Xiao Ming repeated the experiment 10 times and drew a line graph (the two curves represent two objects respectively). From the graph

The conclusion from the overall analysis is: (2 points)

Xiao Zhong did not do the experiment, but imagined a simple thought experiment: Suppose a heavy object and a light object fall at the same time, if When two objects are tied together, two conclusions will emerge:

a. A heavy object carries a light object, and the light object blocks the heavy object, and its falling time is the middle value of the respective falling times of the two objects;

a. p>

b. The two objects together will be heavier than any single object, and the falling time should be shorter than either single object.

Are these two conclusions contradictory? (1 point)

From Xiao Zhong’s thought experiment, we draw the conclusion that (1 point)

In the second semester of the 2006 school year, the seventh grade students of "Science" studied self-learning Test unit exercises

(Final exam paper)

1. Multiple choice questions:

1-5.BCCCC 6-10.ABBBD 11-15.ADAAC 16- 20.ACDBB 21-25.CABBA

2. Fill in the blanks:

26.30 27. Fracture 28. Vegetative reproduction asexual 29. Refraction becomes smaller 30. Equal to 31. Equal to 32.100

No change 0 33. Muscular development, long beard, protruding Adam's apple, etc.; increased fat, enlarged pelvis, developed breast glands, etc. 34.1 35.1

3. Analysis and explanation questions

36. ( 1) Tropic of Cancer (2) Summer Solstice (3) Longer Days and Shorter Nights in Summer 37. (1) I tap my toes and people fly up. (2) When I came to the North Pole, I saw some cute polar bears playing in the snow under the sun.

(3) I looked down and found that the earth rotates clockwise from east to west 38. Xinjiang and Jinhua are in different time zones, so their time zones are also different 39. (1) Stem He Ye (2) 1 (3) Embryo 40.A-F B-D C-E

IV. Experiment and exploration:

41. (1) The car is subject to the friction force of the horizontal surface Effect (2) The relationship between the moving distance of the car and the friction force exerted on it by the horizontal surface (3) The car will move along a straight line forever, and the speed remains unchanged.

(Perform uniform linear motion)

42. Volume shape (reasonable as long as it is reasonable) (a) Shape and volume must have the same mass (b) For the same distance compared to time, whoever has less time will move faster (4) The speed at which an object falls has nothing to do with its mass. The speed at which an object falls has nothing to do with its mass