2. 影响旋风除尘器性能的因素有（） A. （1）二次效应；（2）比例尺寸；（3）物理性质； B. （1）二次效应；（2）比例尺寸；（3）工作参数； C. （1）二次效应；（2）物理性质；（3）工作参数 D. （1）二次效应；（2）比例尺寸；（3）物理性质；（4）工...

14. Our team _____ the visitors in the football match yesterday afternoon. A. got the first of B. got the best of C. took the first of D. took the best of ...

21. After the 90-minute match, all the football players were _____. A. lost B. tied C. exhausted D. exhibited ...

12. As time went on, some products of poor quality were _____out of the market. A. let B. lost C. dropped D. driven ...

3. Last night a fire _____ in that market, so the firm suffered a heavy loss. A. broke up B. broke out C. broke of D. broke down ...

22.??The librarian is arranging the books, which are not in their proper ____. A. line B. turn C. row D. order ...

17.??I think it is hard to _____ what you said. A. ensure B. convince C. agree D. believe ...

12.??Can you tell Mary _____ her twin(双胞胎) sister? A. to B. with C. between D. from ...

7.??Our country has _____ great changes in the last thirty years. A. experienced B. practised C. experimented D. involved ...

2.??It’s almost ____ that Mr. Barry will win the next election. A. certain B. sure C. certainly D. surely ...