Enough sleep is important to health. The amount of sleep __1________(need) depends on the age of the person and the conditions in _2.________ sleep takes place. The young may need more sleep than __3.________ old, but usually eight hours are enough for the health of grown-ups. Some can do with ___4_______ than this amount, but others may need more. Every person knows his own need. ___5_______ is then a matter of good judgment to satisfy his need. Sleep should always be enough to make one bring back his __6.__________ (strong) and get ready for a day’s work.

Fresh air is necessary to sound sleep. So it is not __7.___________ reason for some people to think that it is practicable to sleep in the open air. A bath at bedtime, __8._________ hot nor cool but of body temperature, may be helpful_9._________ sleep. Sleep-producing drug should never be taken except when _10.________ (suggest) by a doctor.

_____ to go abroad, his spare time is totally spent in learning English.

   A. Having intended       B. Intending   C. To intend         D. Because he intends

A notice was placed by the river bank warning people to ___________ the thin ice.

   A. keep off   B. keep out      C. keep away    D. keep on

The government has taken some measures to solve the shortage of electricity, but it may be some time _________ the situation improves.

A. since   B. when   C. unless   D. before

Some pre-school children go to a day care center, __________ they learn simple games and songs.

    A. then          B. there              C. while         D. where

With online course Crazy English has over 20 million students all over China ____ the class through Internet.

A．attend      B．attended      C．attending      D．to be attending

He is only too ready to help others, seldom, _________, refusing them when they turn to him.

A. if never    B. if ever    C. if not    D. if any

——The police have caught the murderer.

   ——Yes, and he admitted ___________his boss on a rainy night seven years ago.

   A. to kill    B to have killed   C having killing   D have been killed

The practice of hanging clothes across the street is a common _________ in many parts of the city.

     A. look             B. sign               C. sight                D. appearance

He expected there ____________ more room for him to put in a desk.

   A. will be        B. is            C. to be           D. being