18、The warmth of ______ sweater will of course be determined by the sort of _____ wool used.

A. the; the                   B. the;不填                    C. 不填;the               D.不填；不填

17、I ______ ping-pong quite well, but I haven't had time to play since the new year.

A. will play                 B. have played                C. played                   D. play

16、A computer can only do _____ you have instructed it to do.

A. how       B. after       C. what             D. when

15、Visitors ______ not to touch the exhibits.

A. will request      B. request      C. are requesting      D. are requested

14、I was really anxious about you. You _____ home  without a word.

A. mustn't leave                                               B. Shouldn't have left

C. Couldn't have left                                        D.needn't leave

13、______ such heavy pollution already, it may now be too late to clean up the river.

A. Having suffered          B. Suffering               C. To suffer              D. Suffered

12、The film brought the hours back to me _____ I was taken good care of in that far-away village.

A. until                           B. that                       C. when                    D. where

11、As we joined the big crowd I got ______ from my friends.

A. separated                   B. spared                    C. lost                       D. missed

10、Selecting a mobile phone for personal use is no easy task because technology _____ so rapidly.

A. is changing    B. has changed       C. will have changed           D. will change

9、The Parkers bought a new house but _____ will need a lot of work before they can move in.

A.they                            B.it                            C. one                       D. which