四、阅读理解。(共20小题;每小题2分，满分40分)

(A)

Skin-diving(潜水)is a new sport today . This sport takes you into a wonderful new world . It is like a visit to the moon ! When you are under water , it is easy for you to climb big rocks , because you are no 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 of air on your back, you can stay in deep water for a long time. But you must be careful when you dive in deep water.

To catch fish is one of the most interesting parts of this sport. Besides(另外) , there are many uses for skin-diving . 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 will take you to           .

A. the moon            B. mountains           C. danger         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 are lighter than on land .       D. there is a lot of fish.

(    )3. Under water , a skin-diver           in the daytime.

A. can see everything 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. drink some clean water              D. have more fun.

(    )5.Which of the following sentences is NOT true ?

A. skin-diving is a new sport.           B. skin-diving is both interesting and useful.

C. skin-fiving is like visiting the moon.   D. The only use of skin-diving is to have more fun.

(B)

The word “day” has two meanings. When we talk about the number of days in a year, we are using “day” to mean 24 hours. But when we talk about day and night, we are using “day” to mean the time between sunrise and sunset. Since the earth looks like a ball, the sun can shine on only half of it at a time. Always one half of the earth is having day and the other half night. A place is moved from day into night and from night into day over and over by the spinning(旋转)of the earth. At the equator(赤道)day and night are sometimes the same length(长度). They are each twelve hours long. The sun rises at 6 o’clock in the morning and sets at 6 o’clock in the evening. For six months the North Pole(北极)is tilted(倾斜)toward the sun. In those months the Northern Hemisphere(半球)gets more hours of sunlight than the Southern Hemisphere(半球). Days are longer than nights. South of the equator nights are longer than days. For the other six months the North Pole is tilted away from the sun. Then the Southern Hemisphere gets more sunlight. Days are longer than nights. North of the equator nights are longer than days. Winter is the season of long nights. Summer is the season of long days.

(    )6.When the Western Hemisphere is having day, the Eastern Hemisphere is having ________.

A. both day and night       B. day 　　        C. neither(既不)day nor night      D. night

(    )7. A place is moved from day into night and from night into day over and over by ________ of the earth.

A. the pushing             B. the pulling       C. the spinning              D. the passing

(    )8. At the equator day is as long as night ________.

A. sometimes             B. never            C. usually                  D. always

(    )9. When the North Pole is tilted toward the sun, the Northern Hemisphere gets ________ sunlight.

A. less                    B. more            C. all                      D. no

(    )10. When it is winter in China, ________.

A. the USA is tilted toward the sun 　　           B. the South Pole is tilted away from the sun

C. the North Pole is tilted toward the sun 　　      D. the North Pole is tilted away from the sun