15. Richard promised to come to attend the lecture, but till now he hasn't _________yet.

A. turned down B. turned up C. turned off D. turned on

16. When crossing the street, remember to watch out _____________cars.

A. at B. for C. to D. of

17. They were walking on the street __________ they noticed an injured dog lying on the pavement.

A. while B. since C. when D. until

18. Li Ming, if I_______ you, I_________ their offer. After all, you are unable to finish the project by yourself.

A. were; accepted B. am; will accept

C. should be; would accept D. were, would accept

19. In the past 5 years, the number of deaths in the traffic accidents ______ by 10% across the country due to the new traffic law.

A. has dropped B. dropped C. had dropped D. was dropping

20. We finally reached the place _________we had spent our childhood years before.

A. which B. where C. when D. whose

21. The news report gave us a detailed _________of President Xi's visit to Russia.

A. collection B. dictation C. organization D. description

22. Sometimes it is hard for people to ________making a mistake and apologize for it.

A. admit B. escape C. risk D. appreciate

23. Many people are willing to give away their money to the children in poor areas, most of ____are hardworking and thirsty for knowledge.

A. that B. which C. who D. whom

24. It seems that she is a(n)___________lady, for she always works long hours every day.

A. energetic B. cheerful C. intelligent D. confident

25. —I think it's necessary for world leaders to discuss how to handle the environmental problems.

—_____________.

A. That sounds good B. Don't mention it

C. I couldn't agree more D. It doesn't matter