（ ）21. Tom has been in the factory _________he left school.
A. when B. since C. as soon as D. whether
（ ）22. The nurse doesn't feel well today, _________ she still works very hard.
A. but B. and C. or D. when
（ ） 23. _______ my mother ________ my sister watches TV plays these days.
A. Either, nor B. Both, and C. Neither, or D. Neither, nor
（ ） 24. He walked ________ fast for us ________catch up with.
A. so, that B. such, that C. enough, to D. too, to
（ ） 25. Lucy knew nothing about it ________ her sister told her.
A. because B. until C. if D. since
（ ） 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
（ ） 27.--Which would you like, rice or noodles? --_______is OK. I'm hungry.
A. Either B. Neither C. Both D. All
（ ） 28. We found ________ necessary to protect the environment.
A. it B. this C. that D. what
（ ）29. The weather in Beijing is cooler than ________ in Guangzhou.
A. this B. it C. that D. one
（ ）30. There is _________in today's newspaper.
A. new anything B. new something C. anything new D. something new