51.As a teacher, you should not () the students from asking questions in class.

A. 　 have the lights turned on

B. 　 be rewarded with milk

C. 　 please their parents

D. 　 be praised

A. 　 A.brain

B. 　 B.heart

C. 　 C.mind

A. 　 it is true that life in New York is much faster than that in any other city

B. 　 people living outside big cities are lazy and miserable

C. 　 most American people enjoy living in the suburbs of big cities

D. 　 those who are busy are not necessarily unfriendly

A. 　 warmly welcomed the abundance of wealth shown by publishers

B. 　 warmly welcomed the enormous amount of creativity shown by publishers

C. 　 showed great enthusiasm in publishers of treat wealth

D. 　 reacted strongly to the unlimited creativity of publishers

A. 　 to

B. 　 against

C. 　 for

D. 　 out

A. 　 at

B. 　 of

C. 　 for

D. 　 with

A. 　 artificial

B. 　 unnatural

C. 　 false

D. 　 unreal

A. 　 maintain a regular pattern of life

B. 　 prevent trouble that comes looking for him

C. 　 avoid danger and inefficient labor

D. 　 restore his bodily functions

A. 　 the Apollo mission was very successful

B. 　 protection from space radiation is no easy job

C. 　 astronauts will have deformed children or grandchildren

D. 　 radiation is not a threat to well-protected space explorers

A. 　 the cheaper a thing is, the poorer the quality will be

B. 　 the court will restrict their ability to represent their client’ s interests

C. 　 the costs to the state of the system as a whole will probably rise

D. 　 the lack of money and time will result in a decline in the quality of their work