longer heavy.

Here，under water，everything is blue and green. During the day，there is enough light. When fish swim nearby，you can catch them with your hands.

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

To catch the fish is one of the most interesting parts of this sport. On the other hand，you can clean the ships without taking them out of the water. You can get many things from the deep sea.

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

26. Skin-diving can take you to _______.

A. mountains

B. the moon

C. the sun

D. the deep sea

27. You can climb big rocks under water because _______.

A. you are stronger

B. the fish can help you

C. there is a lot of light

D. you are not as heavy as on the land

28. A skin-diver _______ under water in the day.

A. can see nothing

B. can see only fishes

C. can see everything clearly

D. can't see anything clearly

29. With a tank of air on your back，you can _______ .

A. have more fun

B. catch fish very easily

C. catch fish with hands

D. stay under water for a long time

30. Which is the best title of the passage?

A. Skin-diving is useful

B. Skin-diving is interesting

C. A new sport: skin-diving

D. Skin-diving is like visiting the moon

C

In China, more and more middle school students are getting shorter sleeping time