When water ________, it will be changed into vapor．

1. A.
   is heated
2. B.
   heating
3. C.
   has heated
4. D.
   heats

根據(jù)對話內(nèi)容，從方框內(nèi)選擇合適的句子補(bǔ)全對話

A: What’s that?

B: (1)_________

A: When was it invented?

B: (2)_________

A: How did it work?

B: (3)_________ They pushed the pedals (踏板) down hard with their feet. (4)_________

A: What was it made of?

B: It was made of wood. (5)_________

A: Yes, I never saw such a machine before.

You can see waste（浪費）everywhere in the school. Some students ask for more food than they can eat and others often forget to turn off the lights when they leave the classroom. They say they can afford these things. But I don’t agree with them.
Waste can bring a lot of problems. Although China is rich in some resources（資源）, we are short of others, for example, fresh water. It is reported（據(jù)報道） that we will have no coal （煤）or oil to use in 100 years. Think about it. I think we should say no to the students who waste things every day. Everybody should stop wasting as soon as possible.
In our everyday life, we can do many things to stop waste . For example, turn off the water taps when we finish washing, turn off the lights when we leave the classroom and try not to order more food than we need. Little by little, everything will be changed. We can stop waste one day if we do our best to form（養(yǎng)成）the habit of saving.
【小題1】From the passage we know that some students often _________ in the school.

 Skin-diving(潛水) is a new sport today. This sport takes you to a wonderful new world. It’s like a visit to the moon! When you’re under the water, it’s easy for you to climb big rocks(巖石) because you aren’t heavy any more.

      Everything is blue and green under the water. During the day, there’s enough light（光）. When fish swim nearby, you can catch them with your hands.

      When you have tanks of air(氧氣罐) on your back, you can stay in deep water for a long time. But you must be careful, when you dive in deep water.

      It’s the most interesting part of this sport to catch fish. There are most uses for skin-diving, too. You can clean ships without taking them out of the water. You can get many things from the deep sea.

      Now you see that skin-diving is both useful and interesting.

1. Skin-diving can take you to ___________.

A. the moon         B. be in danger        C. mountains           D. the deep sea

2.You can climb big rocks under water because _________.

A. you are stronger                         B. the fish nearby help you

C. you aren’t as heavy as on the land(陸地)      D. there is a lot of light

3. Under water, a skin-diver _________ in the day-time.

A. can see anything clearly                    B. can’t see anything clearly

C. can see nothing                           D. can see only fishes

4.With a tank of air on your back, you can _________.

A. catch fish very easily              B. stay under water for a long time

C. be in safe place                   D. have more fun

5. Which of the following is NOT true?

A. Skin-diving is a new sport

B. Skin-diving is like visiting the moon

C. The only use of skin-diving is to have more fun.

D. Skin-diving is both interesting and useful