A model or an experiment in a science class can help students see things which would ______ remain hidden.

    A. otherwise                                                 B. still            

    C. thus                                                     D. therefore   

-------______ either you or he going to visit the exhibition? 

 -------He is. I can't _______ working until 6 o'clock.

      A．Is; knock off                                              B．Are; knock away

      C．Are; knock off                                           D．Is; knock away

_____  the help of our teachers, we ______ the problem.

A Under; took no trouble in solving                    B In; had no trouble at solving

C On; kept no troubles to solve                         D With; had no difficulty solving    

Cheer up, Maria! You can also enjoy _____ you have been dreaming of, if you don’t lose heart.

       A．as a convenient life as                                 B．as convenient a life as

       C．as a life convenient as                                 D．convenient as a life as

Having been attacked by terrorists, ________.

       A. doctors came to their rescue                                B. an emergency measure was taken 

       C. the tall building collapsed                                     D. warnings were given to tourists

        money, he is quite rich, but this does not mean he is happy.

A. As with　　                                                B. In terms of　　       

C. Concerning　　                                           D. In the light of

In dealing with public relations, we should make every effort to prevent the _____ in personality.

       A. contact                                                       B. contrast                  

       C. connection                                                  D. conflict

The general at last got a chance to visit the village,       he used to fight,       he had been dreaming of for years.

A. where; which                                            B. where; that       

C. in which; what                                           D. that; which

John was late for the business meeting because his flight had been__________ by a heavy storm.

A. kept　　　　                                              B. stopped　　　　     

C. slowed　　　　                                          D. delayed

You see, there’s no light on in the classroom，there         be anybody studying there now.

A. can’t                                                      B. mustn’t        

C. needn’t                                                   D. mayn’t