Answers and test questions of the fourth grade lower science People's Education Press

3 sets of review questions and answers for the second volume of fourth-grade science in the new textbook edition

1. Fill in the blanks:

1. To make electric charges flow to form an electric current , two conditions need to be met: one is to have power, that is (power supply); the other is to have (circuit) - current can only flow in the circuit.

2. The electricity we use when doing experiments is (direct current) electricity, and the electricity we use at home is (alternating current) electricity. (220) V electricity is enough to cause electric shock accidents and death. .

3. Materials like copper wire that can pass current are called (conductors), and materials like plastic that cannot pass current are called (insulators).

4. One end of the battery is a copper cap and the other end is a zinc shell. When the two ends are directly connected together with a wire, a short circuit will occur.

5. Observing the flashlight, we see that the flashlight is controlled by a (switch).

6. The germination of broad bean seeds requires sufficient (moisture) and (oxygen) and suitable (temperature).

7. The pollen produced in the stamens (stamens) of the plant is transferred to the stigma (pistil), fertilizing the (ovule) in the ovary of the pistil. The fertilized ovule develops into a seed (seed).

8. A flower composed of four parts (sepals), (petals), (stamens), and (pistils) is called a (complete flower). Flowers that are missing one, two, or three parts are called (incomplete flowers).

9. To know the hardness of minerals, we can use (fingernails), (keys or paper clips), (knives), etc. to scratch the minerals and determine their hardness.

10. The nutrients contained in food are usually divided into (protein), (carbohydrates), (fat), (vitamins), (minerals) and (water).

11. Food spoilage is caused by (microorganisms).

12. Granite is composed of (quartz), (feldspar) and (mica), among which (quartz) is the hardest and (mica) is the softest.

2. Multiple choice questions:

1. Which of the following objects is an insulator (B).

A. Wet cloth B. Dry wooden stick C. Wire

2. Which of the following plants has unisexual flowers (B)

A. Rapeseed Flower B, pumpkin flower C, impatiens flower

3. The seeds that are spread by the wind are (B).

A. Chestnut B. Dandelion C. Xanthium

4. The electricity used by the TV is (A).

A, alternating current B, direct current C, none of them

5. The following foods can be eaten raw or cooked. Which one is (A)

A. Radish B. Pork C. Potato

6. Use iodine method to detect the (C) content of food.

A. Vitamins and minerals B. Protein C. Carbohydrates

7. A certain mineral cannot be carved with a copper key, but it can be carved with a knife. This kind of mineral The hardness of minerals is (B)

A, softer B, harder C, hard

8. After the movement of the earth, the rocks formed by flowing out during volcanic eruptions are ( B).

A. Fossils B. Pumice C. Shale

9. Which of the following statements is correct (B)

A Rocks and minerals are inexhaustible , inexhaustible.

B Rocks and minerals must be protected and rationally utilized.

C Rocks and minerals are unchanged in nature.

10. What makes the light bulb shine in the picture is (C)

A, B, C,

3. True or False Question:

< p>1. The eggs produced by animals can develop into a new generation of life. (Wrong)

2. The human body and the earth are both conductors.

(True)

3. Household electric lights are connected in series, which is more convenient to connect (Wrong)

4. Only stamens and no pistils or only pistils and no stamens. This kind of flower is called hermaphrodite. Flower (wrong)

5. Do not use a wet rag to wipe live electrical appliances. (Yes)

4. Connection questions.

1. Conductor plastic 2. Water flow propagation of cocklebur

Rubber lotus ejection propagation

Air

Insulator copper dandelion propagation by wind

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Animal transmission of impatiens

Human body

5. Picture-filling questions:

1. Write down the parts of the flower in the picture below

6. Practical questions:

1. Please design a nutritious dinner of four dishes and one soup for your family.

Menu

Staple soups

2. Rocks and minerals have many applications in our daily lives. For example, the main component of the pencil lead we use is graphite. , please try to write down several examples of the application of rocks and minerals in life.

The name of the rock or mineral and the application of the rock or mineral

3. There is a box with 4 terminals. Xiao Ming uses a circuit detector to detect the connections between the terminals. The status is recorded in the following table:

Which group of wiring 1——2 1——3 1——4 2——3 2——4 3——4

Pass √ √ √

Open circuit√ √ √

Please guess how the circuits inside are connected based on the test records. Use lines to represent your guessed results in the figure below (if there are multiple The method can use different strokes)

1 2

3 4

7. Extended questions:

1. Please tell me about your usual times. How should we use electricity safely in life?

2. Please design an experiment to prove the role of cotyledons in the seed germination process.

(Paper 2)

1. Fill in the blanks 20%

1. In order to slow down the deterioration of food, usually useful methods include freezing, ( )( ),( )wait.

2. There are two basic connection methods for circuit connection: ( ) and ( ). The lighting circuits in our homes are generally connected using the ( ) method.

3. In a complete circuit, if the small light bulb does not light up, it means that no ( ) passes through the light bulb.

4. The method of reproducing offspring through eggs, such as frogs and chickens, is called ( ), and the animals that reproduce offspring through eggs are called ( ).

5. The voltage of one battery is 1.5V. If two batteries are connected in series, the voltage will be ( ); if two batteries are connected in parallel, the voltage will be ( ).

6. Food spoilage is caused by ( ).

7. Mold growth requires an environment of ( ) and ( ).

8. Among the minerals, the hardest one is ( ) and the hardest one is ( ).

9. Rocks are generally composed of one or several types of ( ). The minerals I know of are ( ), ( ), and ( ).

2. Multiple-choice questions 30%u None

1. Rub and press on the white paper. If there are oil stains left on the white paper, the food contains Rich ( ).

A Protein B Fat C Sugar

2. Which of the following objects can be used to connect a circuit ( )

A. Rubber B. Plastic ruler C. Pencil lead

3. The fruit of a plant develops from the pistil ( ).

A. Style B, ovary C, stigma

4. Among the three minerals of quartz, mica and feldspar, the hardest one is ( )

A. Quartz B, feldspar C, mica

5. The strength of a battery The voltage is 1.5V. The voltage of three batteries connected in parallel is ( )

A, 1.5V B, 3V C, 4.5V

6. Among the following plants, seeds and fruits are spread by wind The plants are ( )

A, philodendron and dandelion B, thistle and dandelion C, tomato and thistle

7. Fossils are generally found in ( )

A. Magmatic rock B. Metamorphic rock C. Sedimentary rock

8. Which of the following objects is a conductor ( )

A. Eraser B. Wet rag C. Piece of paper D. Wood Stick

9. The following incorrect meal matching principles are ( ).

A combination of meat and vegetables B combination of coarse and fine grains C variety combination D fresh fruits are rich in vitamins, so only eat fruits every day

10. The stems and leaves of plants are made from seeds. Developed from ( ).

A, cotyledon B, germ C, embryo

3. True or False Questions 20%

1. Encountering a thunderstorm outdoors Don’t hide under trees to avoid rain…………………………………… (　)

2. The seeds that are spread by animals are long hooks or prickly fruits and seeds… ………………( )

3. The correct way to smell the smell of an unknown object is to gently fan the mouth of the bottle with your hand to allow only a small amount of the smell to drift into your nostrils. …………………………………………………… ( )

4. We found that the flowers of green flowering plants that can bear fruit have no pistils... ………………( )

5. Vitamins and minerals can regulate body functions. ………………………………………………( )

6. Granite is mainly composed of three different minerals: quartz, feldspar and mica………………( )

7. The human body and the earth are conductive……………………………………………………(　)

8. Some minerals Geometric shapes with special rules, it is easy to distinguish them by observing their shapes……………………………………………………………………………………( )

9. Different ways of eating food will affect our absorption of nutrients…………………… ( )

10. Impatiens are generally eaten through Animals spread seeds…………………… ( )

4. Picture-filling questions 24%

1. There is a four-connector After testing the box with a circuit detector, Xiao Ming recorded the connection status between the terminals in the table below.

4%

Which group of wiring 1——2 1——3 1——4 2——3 2——4 3——4

Pass √ √ √

Open circuit √ √ √

Please guess how the wires inside are connected based on the test records. Use lines to represent your guess results in the picture below.

2. Fill in the internal structure of a seed 7%

3. Fill in the structure of a complete flower 4%

5. Connecting questions 5%

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6. Practical questions 10%

1. We have observed rape flowers, speculated on the changes that will occur in the flower buds, and drawn the process from flower buds to blooming in order. 4%

2. Please prepare a delicious and nutritionally balanced recipe for yourself 6%

Answers to the test paper

1. Fill in the blanks

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1. Sun-drying method, pickling method, canning method, 2. Parallel connection, series connection, parallel connection 3. Electric current

4. Oviparous, oviparous animals 5. 3V, 1.5V 6. Microorganisms 7. High temperature and humidity

8 9. Minerals, quartz, feldspar, mica

II. Multiple choice questions

B C B C A B C B D B

III , True or False questions

√ × √ × √ √ √ √ √ ×

4. Picture-filling questions

1

5. Connect Line questions

6. Practical questions (omitted, reasonable points are scored)

(Paper 3)

1. Fill-in-the-blank questions

1 ,A rapeseed flower includes four parts: , , .

2. It is the main component of human muscles, skin, internal organs, hair, nails and blood.

3. The structure of broad bean seeds is divided into , , , and other parts. After the embryo develops and grows, it becomes . After the radicle develops and grows, it becomes . What protects the seed is . What provides nutrients for the germination of the seed is .

4. Use iodine to know whether the food contains more iodine.

5. Commonly used methods for people to store food include , , , , etc.

2. True or False Questions

1. Fish contains all the nutrients our human body needs. ( )

2. In order to obtain a balanced supply of various nutrients, we must not be picky about food. ( )

3. Some people say that eating more fat will make you fat and prone to disease, so we cannot eat foods containing fat, such as fatty meat ( )

4. Eggs produced by animals can Develop into a new generation of life. ( )

5. Rock is very hard and will never change its shape.

3. Multiple-choice questions

1. Rub a certain food on a white paper and press it. If there are oil stains on the white paper, it means that the food contains more ( )

A protein B sugar C fat D vitamin

2. The following things must be cooked and eaten ( )

A cucumber B radish C Pork D Pears

3. Among the following foods, the vitamin-rich ones are ( )

A Mutton B Milk C Carrots D Sausage

4. Each of the following Among the items, the one that is not the structure of broad bean seeds is ( )

A seed coat B radicle C embryonic stem D embryo

5. Which of the following plants uses animals to spread seeds ( )

A coconut B dandelion C impatiens D cocklebur

6. Many vegetables are rich in ( ).

A. Protein B, carbohydrate C, fat D, vitamins, minerals

4. Picture-filling questions

1. Write the various parts of rapeseed flowers name.

5. Design questions

Please design a nutritious dinner

6. Experimental questions.

1. There is a box with 4 connectors. After testing it with a circuit detector, Xiao Ming recorded the connection status between the connectors in the table below.

Which group connects 1-2 1-3 1-4 2-3 2-4 3-4

Pass √ √ √

Break √ √ √

Please guess how the wires inside are connected and draw them in the picture below