31. -How amazing it is that astronauts are exploring outer space.

　 --It’s a challenge, I guess, ________ man against nature.

A. by　　　　　　 B. for　　　　　　 C. of　　　　　　　　 D. about

30. ________a certain doubt among the people as to the practical value of the project.

　 A. It has　　　　　 B. They have　　 C. It reminds　　　　　 D. There remains

29.Every evening after dinner, if not____from work, I will spend some time walking the dog.

　 A. being tired　　　 B. tiring　　　　　 C. to be tired　　　　 D. tired

28. The system has been designed to give students quick and easy________to the digital resources of the library.　

A. access　　　　 B. passage　　　　 C. way　　　　　　　 D. approach

27. Friendship is so sweet and enduring____nature that it lasts through____whole lifetime.　　

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

26. Daniel’s family ________their holiday in Huangshan this time next week.

　 A. are enjoying　　 B. will be enjoying

　 C. are to enjoy　　 D. will enjoy

25.This printer is of good quality. If it ___break down within the first year, we would repair it at our expense.

　 A. should　　　　　 B. would　　　　　 C. could　　　　　　 D. might

24. Please do me a favour--________my friend Mr. Smith to Youth Theater at 7:30 tonight.

　 A. to invite　　　　　 B. inviting　　　　 C. invite　　 　　　　D. invited

23. People _________ hobbies which offer enjoyment, knowledge and relaxation.

A. bring up　 　　　 B. set up　 　　　　　　　 C. pick up　 　　　　　　 D. take up

22. Livemocha. com is a free site 　　　　visitors can not just learn various languages but also chat online.

　　 A. where　　　　　　　　 B. which　　　　　　　　　 C. that　　　　　　　　　　　 D. what