20.The last bus had gone and he　　 home on foot.

A.had no choice but go

B.had no choice but to go

C.had nothing to do but to go

D.had no choice but going

19.We must　　 plants　 　 the cool.

A.protect;from 　　　　　B.prevent;from

C.stop;from 　　　　　　D.keep;from

18.The students are busy 　 their homework.

A.do　　　B.doing　　　C.did　　　D.done

17.　　 time goes by,we learn more and more knowledge.

A.With　　B.When　　　C.Since　　D.As

16. 　by the snake,the girl stood still there.

A.Frightening　　　　B.To frighten

C.Frightened　　　　　D.Frighten

15.All the students were studying in class　　 　Tom;he was playing football on the playground.

A.except　　　　　B.besides

C.except for　　　　D.except on

14.A man 　 unusual foreign clothes went into the lady’s living room.

A.to　　　B.in　　　C.on　　　D.for

13.The doctor wrote him a prescription　　 some medicine.

A.to　　　B.in　　　C.on　　　D.for

12.He quited　　 cigars after he married.

A.smoke 　　　B.to smoke　　C.smoking　　D.smoked

11.They　　 each other for 5 years.

A.have been in love with　　　B.have fallen in love with

C.are in love with　　　　D.fell in love with