7、　　　 we humans are alone in the universe,scientists have scanned the sky for outer space signals and sent messages out into space.

A、We wonder if　　 B、Having known that　　　

C、To find out whether　　 D、Not knowing why

6、When first　　　 to the market,these products enjoyed great success.

A、introducing　　 B、introduced　　 C、introduce　　 D、being introduced

5、The flowers　　　 sweet in the botanic garden attract the visitors to the beauty of nature.

A、to smell　　　 B、smelling　　　 C、smelt　　　　 D、to be smelt

4、　　 pity on the snake led to his own death.

A、The farmer to take　　 B、The farmer taking　　　

C、The farmer’s taking　　　 D、The farmer took

3、She left him,　　　 in that house again.

A、determined never to set　　 B、not to be determined to put　　　

C、determining not placing　 D、not having determined by fixing

2、Rainforests　　　 and and burned at such a speed that they will disappear from the earth in the near future.

A、being cut　　　 B、are cut　　　 C、to be cut　　　 D、are being cut

1、John ofen attends public lectures at the University of Oxford,mainly　　　 his English.

A、to improve　　 B、improving　　 C、having improved　　　 D、to have improved

15、　　　 the best in a recent science competition,the three students were awarded scholarship　　 21,000 dollars.

A、Having judged;to total　　 B、Judged;totaling　　　

C、To be judged;totaled　　 D、Judging;would total

1-----5DACCB　　 6-----10DBCAD　　　 11----15CCCCB

精练四

14、John Smith,　　 by two companies,is planning to have a third try.

A、being turned down　 B、refused　　 C、having been turned down　　 D、to be refused

13、The flu is believed　　 by viruses that like to reproduce in the cells inside the human nose and throat.

A、causing　　 B、being caused　　　 C、to be caused　　　 D、be have caused