20、Pop music is such an important part of society ______ it has even influenced our language.

A. as       B. that     C. which       D. where 

19、After a knock at the door, the child heard his mother’s voice ______ him.

A. calling B. called  C. being called       D. to call

18、There is nothing more I can try ______ you to stay, so I wish you good luck.

A. being persuaded   B. persuading   C. to be persuaded   D. to persuade

17、The Town Hall ______ in the 1800’s was the most distinguished building at that time.

A. to be completed                                       B. having been completed 

C. completed                            D. being completed

16、His movie won several awards at the film festival, ______ was beyond his wildest dream.

A. which      B. that      C. where         D. it 

15、Small sailboats can easily turn over in the water ______ they are not managed carefully.

A. though             B. before   C. until    D. if

14、______ he referred to in his article was unknown to the general reader.

A. That   B. What   C. Whether     D. Where

13、The traditional view is ______ we sleep because our brain is “programmed” to make us do so.

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

12、At minus 130℃, a living cell can be ______ for a thousand years.

A. spared B. protected    C. preserved   D. developed

11、Since Tom ______ downloaded a virus into his computer, he can not open the file now.

A. readily B. horribly      C. accidentally       D. irregularly