21、____ sat down for a rest       the door bell rang.

A. Hardly I had; when    B. Hardly I had; than      C. Hardly had I; than     D. Hardly had h when

20、      a nice man        that we all believe him.

A. Such; did he seem     B. So; did he seem        C. Such; he seethed       D. So; he seined

19、So funny ___ that everyone burst into laughing.

A. she looked           B. was she looking        C. did she look          D. had she looked

18、Only after reaching eighteen       join the army.

A. have you; you can     B. have you; can you      C. you have; you can     D. you have; can you

17、The students       on the professor’s lecture now and then.

A. took note           B. took notes                C. took notice                D. took action

16、The town’s drinking-water _____ with prim chemicals at present.

A. contaminates     B. is contaminated     C. is being contaminated    D. has been contaminated

15、 I feel that it was time for me to ____.

A. take actions          B. take an action          C. take the action       D. take action

14、They        their side of the field very well.

A. defended           B. protected                 C. keep                    D. prevent

13、Her father gave her the ___ of going on to college or starting to work.

A. chance             B. opportunity                C. alternative             D. possibility

12、He soon found himself       his new co-workers.

A. in harmony of        B. in the harmony of       C. in harmony with     D. in the harmony with