Sleep is something we all do.But some people need to sleep more than others.Babies sleep most of the time.Children in school sleep about ten to twelve hours a night.Most grown­ups sleep only seven or eight hours.__1__

All parts of our bodies have to rest after they work.Our arms need a rest after we lift heavy things.When we run fast，our legs work hard.They get tired.We have to rest them.Our brains work hard，too.__2__ We can sit quite still and rest our arms and legs.But our brains aren't resting.They go right on thinking as long as we are awake.

Our brains slow down a bit when we sleep and dream.__3__ Instead of thinking wide­awake thought，our brains make up dreams.Some dreams are very pleasing.Some are not.Most of the time we forget them when we wake up.

Scientists have tried to find out what would happen if people were not allowed to sleep.They asked some people not to go to bed.The people stayed up all night and all the next day.They stayed up the next night，too and the day after.They played games.But they made mistakes.They forgot things.__4__.The people grew rude and mean.They became angry with their friends.Finally they were too tired to stand up.The moment they sat down，they fell asleep.

Scientists found that if people are not allowed to sleep，they act in an unusual way.__5__ But we do know that we need it to stay well.

So tonight have a good sleep.Lie down under the covers.Shut your eyes.Let your thoughts travel about.Soon you'll stop thinking.You'll be asleep.

A．But even as we sleep our brains are doing some work.

B．It was hard for their tired brains to work.

C．When we are awake，they help us pay attention to the world around us.

D．No one knows quite surely why sleep is so good for us.

E．Good sleep helps to improve one's memory.

F．But babies，children and grown­ups-all of us need to have our sleep.

答案：1.F　2.C　3.A　4.B　5.D

15．The agreement indicates that the two companies will

________ with each other again.

A．team up　 　　　　　　　　　　　　　　　　　 B．turn up

C．look up　 　　　　　　　　　　　　　　 D．pick up

答案与解析：A　team up with“与……合作或一起工作”为固定搭配。turn up“出现；露面”；look up“向上看”；pick up“捡起”。

14．The digging will seem easier if you divide up the garden by marking ________ small sections with your spade(铲子)．

A．down　 　　　　　　　　　　　　　　　　 B．up

C．out　 　　　　　　　　　　　　　　　　　　　　　 D．with

答案与解析：C　mark out“划线标出……的界限”。

13．-Oh，dear.What happened?

-I ________ on the shiny floor and fell.

A．skipped　 　　　　　　　　　　　　　　 B．jumped

C．attacked　 　　　　　　　　　　　　　　　　　 D．slipped

答案与解析：D　slip“滑倒”。答句句意：我滑倒在发亮的地板上了。skip“跳跃”；jump“跳跃”；attack“攻击”。

12．Their ________ grief turned to crazy laughter in a minute.

A．apparent　 　　　　　　　 　　　　　　　 B．crazy

C．stable　 　　　　　　　　　　　　　　　　 D．invaluable

答案与解析：A　apparent表示“显然的，外观上的”。句意：他们那假意的哀伤很快就变成了一阵阵狂笑。crazy“疯狂的；狂热的”；stable“稳定的”；invaluable“无价的”。

11．Look！There are ________ grazing over there.

A．two cattles　 　　　　　　　　　　　　 B．two head of cattle

C．two cattle　 　　　　　　　　　　　　　 D．two heads of cattle

答案与解析：B　cattle是牛的总称，集合名词，two head of cattle两头牛是固定短语。

10．(2011·胶州诊断)He's an intelligent boy.He ________ made such a foolish mistake.

A．can't have　 　　　　　　　　　　　　　 B．may not have

C．might not have　 　　　　　　　　　 D．mustn't have

答案：A

9．He didn't ________ what I read because his mind was on something else.

A．hold on　 　　　　　　　　　　　　　　 B．catch on

C．take in　 　　　　　　　　　　　　　　　 D．get over

答案与解析：C　take in 理解。hold on(打电话时)不要挂断；catch on 明白，作不及物动词用，catch on to 懂得，明白，作及物动词用；get over 克服。

8．Most film directors can have a proper ________ to public opinions on their films.

A．reaction　 　　　　　　　　　　　　　　　　　 B．role

C．imagination　 　　　　　　　　　　　 D．idea

答案与解析：A　reaction(to)对……的反应。句意：大部分导演对于公众对他们电影的看法反应恰当。role“角色”；imagination“想象”；idea“观点”。