In Britain,sales of cigarettes have been reduced __________ 30% in the past ten years.

A.for             B.to        C.from           D.by

Playing tricks on others is __________ we should never do.

A.anything            B.something          C.everything          D.nothing

The professor walked onto the platform and seated himself in a chair, ____ for answering questions.

A、had prepared B、being prepared   C、preparing    D、prepared

His family ____ a large one. The whole family ____ watching TV. 

A．is…is　               B．a(chǎn)re…are　           C．a(chǎn)re…is　          D．is…are

The cattle _______ grazing on the grass.

A. were                   B. was                      C. be                     D. is

Not until the child fell asleep_______leave the room.

A.did the mother                          B. does the mother

C. was the mother                         D. is the mother

I can never forget the day _______ we worked together and the day ______ we spent together.

A. when; which       B. which; when       C. what; that          D. on which; when

Doris' success lies in the fact _______ she is co-operative and eager to learn from others.

A. which                B. that                      C. when                   D. why

In 1927 Benjamin Franklin founded one of the first adult-education organizations, ____ the Junto.

A、has been called  B、to call  C、a group called   D、which group called

Investigators are still trying to determine the __________ of the accident.

A.cause          B.problem             C.reason         D.puzzle