The doctor will not perform the operation ___ it is absolutely necessary.

A. when               B. if                  C. for                  D. unless

___ difficult the task may be, we must fulfil it this month.

A. No matter how B. No matter what       C. No matter when   D. No matter where

We can’t feel that we are going forward as everythjng us is moving the same speed．

A．around；at B．around；with C．before；at D．with；in

I was angry _______ him for keeping me waiting.

A. with    B. to   C. about     D. on

  11. —Would you like to come to dinner tonight？

    —I’d like to, ___ I’m too busy.

    A. and . B. so

    C. as. D. but

I'd like to go swimming ____ the water is not too cold.

A. for               B. unless             C. if                D. whether

____ you work, you must always serve the people heart and soul.

A. Wherever                  B. Whenever            C. Where                D. When

I wanted two seats Madame Curie for Friday night，so I rang the cinema to see if I could book two tickets．

A．of B．about C．to D．for

It rained heavily,____ the basketball match had to be put off.

A. so that                   B. when                  C. otherwise        D. therefore

____ he was in poor health, he worked just as hard as everyone else.

A. But             B. Although              C. Even if        D. If