21. ___ an answer from her husband, Emily decided to send him another email.

A.　　　 Not having received　 B. Having not　　 C. Receiving not　 D. Not receiving

20. Peter sat under a tree and seeing his friend, ____ up in no time.

A. to stand　　　　 B. standing　　　　　　 C. stood　　　　 D. would stand

19. The law requires governments to increase investment in public transport, ___services and encourage people to use public transport.

A. improved　　　 B. to improve　　　　 C. 　improving　　　 D. have improved

18. --- ____your car here, or you’ve got to be fined.

--- But where on earth can I park ?

A. Not parking　　　 B. Parking　　　　 C. Don’t park　　　 D. Park

17. The old man spoke to the girl again, raising his voice a bit, but still ＿＿no answer.

A. received　　　　　 B. receiving　　　 C. had received　　 D. to receive

16. Tom stood there, ____ what he could do for the poor old man sitting beside him.

A. 　 wondered　　　 B. wondering　　　 C. to wonder　　　　 D. having wondered

15. So many directors ____, the boarding meeting had to be put off.

A. 　 were absent　　 B. been absent　　 C. had been absent　　　 D. being absent

14. While building a tunnel through the mountain, _____.

A. the workers discovers discovered

B. an underground lake was discovered

C. there was an underground lake discovered

D.　　 the lake was discovered underground

13. It rained for two weeks on end, completely ____ our holiday.

A. 　 ruined　　　 B. ruining　　　 C. to ruined　　　　 D. ruins

12. ____the safety of gas, the government has checked the city’s gas supply system thoroughly.

A. To ensure　　　　　 B. Ensuring　　　　 C. Having ensured　　　　 D. To have ensured