28. We found _____ necessary to protect the environment.

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

27.--Which would you like, rice or noodles?

　--______is OK. I'm hungry.

A. Either　　 B. Neither　　　 C. Both　　　 D. All

26.(　　 )I don't think it very expensive to buy a family computer here.

　　　 -- Really? I'll buy ____ next week.

A. it　　　 B. this　　 　C. one　　 　　D. mine

25. Lucy knew nothing about it ______ her sister told her.

　 　A. because　　 　B. until　　　　 C. if　　 　　　D. since

24. He walked ______ fast for us ______catch up with.

　　 A. so, that　　 B. such, that 　C. enough, to　　 D. too, to

23. ___my mother ____ my sister watches TV plays these days.

　　 A. Either, nor　 B. Both, and　 C. Neither, or　 　D. Neither, nor

22.(　　 ) The nurse doesn't feel well today,____ she still works very hard.　 　

　A. but　　　 B. and　　　　 C. or　　　 D. when

21.(　　 ) Tom has been in the factory ______he left school.

　　 A. when　　 B. since　　 C. as soon as　 　　D. whether

20.(　　 ) He had ______ much work to do that he couldn't go out.

　　 A. so　　 　　B. such　 　　　C. as　　　　　 　D. or

19. ______the new computer, travellers at the offices of CAAC can now buy their air tickets much faster. 　

A. Because　　 B. Thanks for　　 C. Thanks to　　 　D. Since