The final examination paper of science in the fourth grade of primary school.

1. There is no limit to the solubility of soluble substances in water. ( )

2. The dissolution rate is only related to the substance itself and has nothing to do with other conditions. ( )

Alcohol can be dissolved in water, but water can't be dissolved in alcohol. ( )

Air is insoluble in water. ( )

We usually use the internal flame of alcohol lamp to heat objects. ( )

6. Put two pieces of soap into a cup filled with water at the same time. They must dissolve quickly in hot water. ( )

7. We can separate the salt dissolved in water by filtration. ( )

8. When sugar is dissolved in water, it is sweetest in the middle. ( )

9. In the experiment, "Can stirring speed up the dissolution of salt?" The water in the two cups can be different. ( )

10. In the experiment of "Comparing the influence of water temperature on salt dissolution rate", we can stir in one of the cups. ( )

1 1. Dissolution means that the substance put into water is completely mixed with water, and there is no sediment in the water. ( )

12, put salt water in the sun, or separate salt from water. ( )

13 All liquids are soluble in water. ( )

14, the highest temperature of alcohol lamp is the flame core. ( )

15, baking soda is more soluble in water than salt. ( )

16, the function of asbestos net is to make objects heat faster. ( )

17, soap powder, chicken essence, flour and liquor can all be dissolved in water. ( )

18. Some liquids are insoluble in water but soluble in other liquids. ( )

19. Under the same conditions, the solubility of different substances in water is different. ( )

20. In order to filter more liquid, the liquid in the funnel can exceed the edge of the filter paper. ( )

1. Auricles can amplify sound. ( )

2. Ears can be used for a long time, so you can also use earplugs to listen to songs for a long time ()

Noise will only affect our hearing, and it has little to do with health. ( )

The shorter the distance between the ruler and the desktop, the louder the sound. ( )

All kinds of sounds we hear are mainly transmitted through air, but solids and liquids can also transmit sounds. ( )

6. Objects can generally transmit sound, and their ability to transmit sound is different. ( )

7. You can hear the sound by tapping the desktop with your hand, but you can't see the desktop vibrating, which means that the desktop doesn't vibrate when the sound rings. ( )

8. Noisy and harsh sounds belong to noise. ( )

9. The knocked tuning fork splashed in the water because it was vibrating. ( )

Thunder reached our ears through the sound of rain. ( )

1 1. The sound emitted by an object can be controlled. ( )

12 is the ossicle in the ear, which can convert sound waves into vibrations. ( )

13, the greater the vibration amplitude of the object, the higher the sound. ( )

14, the sound is related to the vibration speed of the object. ( )

15, sound can spread in all directions. ( )

1. Normally, the temperature is the highest in the afternoon. ( )

The northwest wind blows from southeast to northwest. ( )

3. The weather refers to the atmospheric conditions in the area where we live for one month. ( )

4. The forms of precipitation include rain, snow, hail and fog. ( )

5. The flat stratiform clouds formed near the earth's surface are cumulus clouds. ( )

6. Meteorologists often classify wind speed as 12. ( )

7. The weather is constantly changing, which affects all living things on the earth. ( )

8. At the same time, the temperature is the same everywhere. ( )

9. By analyzing the weather calendar, we can find some laws of weather changes. ( )

10, when the sky is covered by clouds for about a quarter, it is cloudy at this time. ( )

1 1. In the container of the rain gauge, the height of the water surface is the precipitation. ( )

12. It rained moderately today. I know that the rainfall is between 25 and 50 millimeters.

13. On a clear day, there are no clouds in the sky. ( )

14, temperature, wind direction, precipitation and cloud cover are all important recorded data in the weather calendar. ( )

15, the arrow of the weather vane points to the north, which is the north wind. ( )

1, body work requires the participation of multiple parts at the same time, which can only be completed by * * *. ( )

When the arm bends and stretches, the movements of bones, joints and muscles are the same. ( )

3. Bones can support the body, protect internal organs and transport nutrients. ( )

All the gases we exhale are carbon dioxide. ( )

5. Exercise can increase vital capacity and strengthen myocardium. ( )

6. The myocardium of the heart contracts and blood returns to the heart. ( )

7. After food enters the human body, it passes through the mouth, esophagus, stomach, large intestine and small intestine. ( )

8. The primary digestion of food in the mouth is completed by teeth, tongue and saliva. ( )

9. The human body consumes a lot of oxygen during exercise, so the number of breaths will increase. ( )

10. During exercise, the heart needs to deliver more oxygen to the whole body. ( )

1 1, the nutrients in food are absorbed in the stomach. ( )

12. Different shapes of teeth play different roles in the process of digesting food. ( )

13. In respiratory organs, trachea is a place for gas exchange. ( )

14. When you digest food, you don't need oxygen. ( )

15, protein in food can be preliminarily digested by the stomach. ( )

Third, I will choose

1, the following objects, insoluble in water is ().

A. monosodium glutamate B. soy sauce C. alcohol D. edible oil

2, the following statement is wrong ().

A. pay attention to the safety of alcohol lamps. Put out the alcohol lamp before the salt water completely evaporates.

C put the evaporating dish on the table by hand immediately after heating.

D. The salt particles in the evaporating dish are very small.

There is undissolved salt at the bottom of a cup of concentrated brine. Which of the following methods can we use to dissolve the salt () at the bottom of the cup?

A. keep stirring B. add water to the cup C. evaporate the water in the cup

4. Put a cup of strong brine on the windowsill to make the water in the cup evaporate. If the water in the cup evaporates, the salt that was originally dissolved in the water ().

A.it's gone. It evaporated like water. B. it won't evaporate, but it will stay at the bottom of the cup.

5, a few drops of oil in the water, the oil will ().

A. Floating on water, but insoluble in water.

B. Submerged at the bottom of the water, but insoluble in water C. Soluble in water.

6. Which of the following methods can separate salt from water? ( )

A. dissolving B. melting C. heating D. filtering

7, the following groups of substances, () can be dissolved in water.

A. salt, vegetable oil B. oxygen, soy sauce C. crystal sugar, flour

8. I observed the phenomenon of (), indicating that flour is insoluble in water.

A. the flour is out of sight. B leave the flour on the filter paper. C. the water turned white.

9. I observed the phenomenon of (), indicating that glue is soluble in water.

A. potential bottom B. floating on the water C. evenly distributed in the water.

10, the following questions, we can directly study is ().

A. How much sugar can a glass of water dissolve B. How many grams of sugar can a glass of water dissolve C. 100 ml of water can dissolve how much sugar.

1. Sound cannot propagate in ().

A. vacuum of solid b, liquid c and gas d

2. The following statement is wrong ().

A keep quiet when talking in hospitals, restaurants and classmates.

B hit the big tuning fork and the small tuning fork with the same force, and the big tuning fork makes a strong sound.

C. Singing and speaking are mainly due to the vibration of vocal cords.

3. Sound in the following objects, the speed of propagation from slow to fast is arranged correctly ().

A. water-gas-wood-steel B. gas-water-wood-steel

C. gas-wood-water-steel D. water-gas-steel-wood

4. In a cup, while slowly adding water to the cup, while constantly tapping the cup wall at the top of the cup, the sound made by the cup will be ().

A. Higher and higher B. Lower and lower C. Same height D. First high and then low

5. The sound of writing can be transmitted to the ear near the desktop through ().

A, pen b, air c, desktop d, paper

6. There is a () in our ear that receives all kinds of sounds and keeps vibrating.

A, tympanic membrane B, ossicles C, cochlea

7. The tighter the rubber band is pulled, the louder the voice is when plucking ().

A, high b, low c, not necessarily heard of it.

8. Extend the ruler out of the desktop for a certain length, and stir the ruler hard to hear the sound ().

A, weak b, low c, high d, strong

9, sound is spread in the form of ().

A, airflow b, straight line c, wave

10, the relationship between pitch and object vibration is ()

A, the object vibrates quickly and the sound is high; B, the object vibrates slowly and the sound is high.

C, the object vibration amplitude is large, and the sound is high. D. The vibration amplitude of the object is small and the sound is high.

1. When recording wind speed, the number "1" means ().

A, no wind b, light wind c, strong wind

2. When the arrow of the weather vane points to the north, the wind direction is ().

A, Dongfeng B, Beifeng C, Nanfeng

There was a heavy rain yesterday, and I know the precipitation is between () millimeters.

a、50~ 100 B、 10~25 C、25~50

4. The cloud that looks like a cotton pile is called ().

A, cirrus b, cumulus c, stratus

5. In the weather symbol below, () means cloudy.

B.C.

6. The distance the wind travels per second is called ().

A, wind speed b, wind direction c, air volume

7, () is a device for measuring precipitation.

A, water collecting funnel b, measuring water pipe c and rain gauge

8. The following cloud amount indicates cloudy ()

B.C.

9. Xiaoming saw the smoke in the chimney drifting to the northwest, and the wind direction at this time was ().

A, northwest wind b, southeast wind c, southwest wind

10. Among the following weather phenomena, () is not in the form of precipitation.

A, heavy snow b, moderate rain c, freezing

1. Among the following statements, () is incorrect.

First, in the exhaled gas, oxygen is reduced.

B, the gas we exhale is carbon dioxide.

C. Breathing is actually a gas exchange.

2. The most important digestive organ for digesting food and absorbing nutrition is ().

A, oral cavity b, stomach c, small intestine

3, in the respiratory organs, () is the place to exchange gas.

A, bronchus B, trachea C, lung

Breathing and heartbeat will be accelerated after exercise. This is because ().

A, you need more nutrition during exercise. B, people are too tired when exercising. C, need more oxygen when exercising.

5, the role of teeth in the process of food digestion is ()

A, bite food b, digest starch c, stir food.

Fourth, I will connect.

Flour dentistry

Digestive organ of sugar heart

Alcohol trachea

Water-soluble glue is insoluble in water, large intestine and respiratory organs.

Soap lung

Sauce stomach blood circulation tube

Plastic blood vessel

Shampoo nasal cavity

The ear canal converts sound waves into a vibrating mouth to temporarily store food and preliminarily digest protein.

The eardrum transmits vibration to the stomach of the inner ear and food to the stomach.

The ossicles transmit sound waves to the middle ear and esophagus to break up food and digest a small amount of starch.

The cochlea transmits auditory signals to the main place where the large intestine of the brain digests food and absorbs nutrition.

The auditory nerve converts vibration into auditory signals, and the small intestine absorbs water from food scraps.

Beat the drum hard

Beat the drum gently

Hear the sound high.

The rubber band vibrates quickly.

The sound you hear is very low, and the rubber band vibrates slowly.

A ruler that sticks out far from the table when you hear a strong sound.

Turn the ruler over close to the desktop.

Hear a faint sound.

Tap the tuning fork

Tap a small tuning fork

Fifth, I will explore

1. Describe the dissolution of five substances in water.

potassium permanganate

flour

glue

edible oil

alcohol

2. Study how to speed up the dissolution of candy in water (a method).

The problem of research

I guess

Required materials

Experimental process

Experimental phenomenon

Experimental conclusion

3. Study how much salt a glass of water can dissolve.

The problem of research

Required materials

research method

research results

4. Use rubber band or steel rule to study the change of sound level.

Research process

Research conclusion

5. Write three ways to separate salt dissolved in water.

6. Write three ways to slow down the dissolution of substances.

7. Draw weather symbols of four different weather phenomena.

8. Write down three ways for people to reduce noise.

9. Under normal circumstances, what is the law of temperature change in a day?

10, which organs of the human body need to work together when skipping rope?

1 1. Write down the names of the filtering device, the evaporating device of the evaporating dish and the alcohol lamp.

12, write the names of various parts of human appearance, as well as the names of various parts of human digestive organs and respiratory organs.