24、--- The door was open.

 --- It ____ open. I had locked it myself and the key was in my pocket.

A. can’t be              B. mustn’t be       C. can’t have been   D. mustn’t have been

23、― Is Mr Smith rich?

― Yes, very rich. When he worked in ________town, he earned a lot. Now he has a big farm in ________ country.

A. at; the　　　　 B. /; /　　　　　　      C. /; the　　　　 D. the; /

22、He had little idea that it was getting so late, ________?

　　A. didn’t he　　　 B. wastn’t it　　     C. did he　　　　   D. was it

21、____ is the case with humans, animals also love their babies.

A. Which                     B. When                      C. What                D. As

20、I enjoy ____ when the sun shines bright and then I can take a walk on the beach.

A. it                            B. that                  C. this                  D. them

19、Persons under 18 ____ not be employed in night work in the United States.

A. can                  B. may                 C. will                  D. shall

18、--- Why did Miss Li leave the job?

--- She ____ for higher wages, but was turned down in the end.

A. broke off          B. gave away               C. held out            D. picked up

17、--- Why do you look worried?

--- Fred left the company half an hour ago. His work ____ unfinished since.

A. left                   B. was left            C. has left                    D. has been left

16、In our school, many a boy ____ playing football and more girls than one ____ playing it.

A. likes; likes          B. like; like            C. like; likes          D. likes; like

15、

--- You know Jane?

--- Yes, it was ____ I surfed the Internet last week.

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