A recent survey of 2000 parents in Britain showed that they are often afraid of science questions asked by their curious children only because they have no idea what the answer is. Here is a list of some simple questions that you can ask your parents to see if they know the answers.

    Q: Why is the sky blue?

    A: You probably know white sunlight is made up of seven colors. While it moves in a straight line when going through space, it starts to divide as it hits “raised area” in the atmosphere. The ones with longest wavelengths pass through easily. The blue , however , can be taken in by the gas molecules (分子) because it has a shorter wavelength , which in turn scatters (使分散) it in different directions. That’s why when you look up at the sky, it appears to be blue.

    Q:Why does the moon sometimes appear during the daytime?

    A: The simple answer to that is because just like any other object it is being lit by the sun. As long as it is around 45 degrees or even 90 degrees off the sun, it will receive light and be able to be seen. The only time it is not able to be seen during its 28-day orbit (轨道) around the earth is when it is right between the earth and the sun. That’s because its back , which is not lit by the sun, is facing us.

    Q: Where do birds/ honeybees go in winter?

    A: While the bird part is quite easy, since a lot of them get together and travel, the honeybee part is likely to puzzle your parents. It turns out that these busy insects stop being that active when the temperature drops below 50°F. Instead ,they get together in the lower central area of the hive （蜂巢）and form a ball around their queen. This helps keep both warm enough to survive the cold winter months.

1.The sky looks blue mainly because the color blue in the sunlight_______.

A. has the longest wavelength among all the colors

B. cannot be taken in by the gas molecules

C. doesn’t hit “raised area” in the atmosphere

D. cannot pass through space successfully

2.How long can’t the moon be seen during the daytime in a month?

A. 2                             B. 28                           C.30                                      D. 31

3.What do honeybees choose to do when the temperature drops below 50°F?

A. They choose to be active in the wild.

B. They choose to keep themselves warm.

C. They choose to travel to a warm place.

D. They choose to get together in the upper central area of the hive.

4.What is NOT explained in the passage?

A. Why is the sky blue?

B. Why is the moon able to be seen during the daytime?

C. Why do birds travel in winter?

D. Where do honeybees go in winter?

　　The world is not only hungry, it will also be thirsty for water. About 97% of water on the earth is sea water, or salty(咸的) water. Man can only drink or use the other 3% of the fresh water(淡水) which comes from rivers, lakes and underground.

The sea is very big. Look at the map of the world, there is more sea than land. It covers(覆盖) quarters of the earth, it looks very beautiful when the sun is shinning on it. But it can be terrible when there is a strong wind.

Some parts of the sea are very deep. There is one place near Japan. It's nearly 11 kilometers high. If we put that mountain into the sea at that place, there would be 2 kilometers of water above it!

The sea is salty. There is one "sea" called the Dead Sea. The Dead Sea is not a sea. It's a big lake in the Jordan Valley. It's the saltiest. It's near the city of Jericho. It's about 80.kilometres long, between 4.8 and 17.7 kilometers wide. The river Jordan runs into the Dead Sea. The sun is not there and the water is salty. Fish can't live in the Dead Sea and plants can't grow near it. People can't swim well in the Dead Sea, but they can't float(漂浮) on the water. The water is very blue and the air is clean. In winter, people come to the Dead Sea to enjoy the sunshine.

(   )26. Does the fresh water come from rivers, lakes and underground?

A. Yes, it does.        B. No, it doesn't.    C. Yes, it doesn't.    D. No, it does.

(   )27. The deepest place in the sea is near        .

A. Japan        B. India        C. America      D. China

(   )28. The passage tells us the sea covers          of the earth.

A.3%            B.25%          C.75%           D.97%

(   )29. The Dead Sea is        .

A.80 kilometers long            B.2 kilometers wide

C.11 kilometers deep            D.17.7 kilometers high

(   )30. According to the passage, which of the following isn't true?

A. The river Jordan runs into the Dead Sea.

B. The world will be thirsty for water.

C. The sea looks beautiful when the sun-is shining on it.

D. The Dead Sea is the saltiest sea in the world.

It is cloudy. Zhang Qiang flies his kite on the playground. He is very happy. But it is raining now. He can't fly his kite. His shirt and trousers are wet. He doesn't want to go home. Ten minutes later, the sun is shining. It is warm now and Zhang Qiang has a good idea. He takes off his wet clothes and ties them to the long string of the kite. He flies his kite and clothes. So they are dry. He puts them on and there is a smile on his face. What a clever boy!

(  )26. Zhang Qiang ______ on the playground.

   A. flies his kite    B. flies his plane    C. runs    D. plays

(  )27. Zhang Qiang wears ______. 

A. a shirt and trousers  B. a shirt and shoes C. a skirt and trousers D. a skirt and shoes

(  )28. Zhang Qiang ties his wet clothes ______ to make them dry.

   A. to a tree    B. on his head    C. to the kite string    D. to his arm

(  )29. It is ______ that day.    

A. rainy, foggy and sunny     B. cloudy, rainy and foggy

C. cloudy, foggy and sunny    D. cloudy, rainy and sunny

(  )30. Zhang Qiang is a ______ boy.

A. lazy    B. good-looking     C. clever     D. tall

The sea looks very beautiful when the sun is shining on it. It can be very terrible when there is a strong wind. The sea is very big. It covers three quarters of the earth. The sea is also very deep in some places. There is one place, the sea is about 11 kilometres there. The highest mountains in the world is about 9 kilometres high. If the mountain was put into the sea at the place, there would still be 2 kilometres of water above it.

In most parts of the sea, there are a lot of fishes and plants. Some live near the top of the sea. Others live deep down. There are also a lot of small living things and a lot of fish by eating them. The sea can be very cold. When people go down, the sea becomes colder and colder. Only some men go down into the deep sea. But in 1970, five women scientists lived in the deep sea for fourteen days.

26. The sea looks beautiful when it is ________.

A. sunny B. rainy C. windy D. cloudy

27. The sea covers ________ of the earth.

A. one third B. three fourth C. one fourth D. two third

28. If you put the highest mountain in the world into the sea, ______.

A. the sea will become deeper B. the sea will become bigger

C. the sea can’t be seen D. the sea can still be seen

29. Lots of fish live in the sea by eating ________.

A. fish B. plants C. small living things D. water

30. _______ have once lived in the deep sea.

A. Only some men B. Only some women

C. Some men and women D. No one

The sea looks very beautiful when the sun is shining on it. But it can be very terrible when there is a strong wind. The sea is very big. It covers three quarters of the earth. The sea is also very deep in some places. In one place, the sea is about 11 kilometres deep. The highest mountain(山) in the world is about nine kilornetres high. If that mountain was put into the sea at that place, there would still be two kilometres of water above it!

In most parts of the sea,there are plenty of fishes and plants (植物). Some live near the top of the sea.Others live deep down. There are also a lot of small living things,and lots of fish live by eating them. The sea can be very cold. When people go down, the sea becomes colder and colder. Only some men can go down into the deep sea. But,in 1970,five women scientists lived in the deep sea for fourteen days.

1.This writing is ________.

2.Which of the following is NOT true?

3.The sea covers _________of the earth.

4.There are a lot of small living things in the sea,and_______.

5.In 1970,five women lived in the deep sea for 14 days. That showed_______.