8. This tree _______ by my father in 1990.

　A. is planted

　B. is planting

　C. was planted

　D. was planting

7. Your homework must _______ before dinner.

　A. finish

　B. be finishing

　C. have finished

　D. be finished

6. The lost child _______ last night.

　A. was found

　B. was founded

　C. has found

　D. has been found

5. A new factory _______ in my hometown soon.

　A. will built

　B. will build

　C. has built

　D. will be built

4. Wait a moment. Your bike ______ now.

　A. is repairing

　B. is repaired

　C. is being repaired

　D. has repaired

3. This kind of machine _______ in China.

　A. makes

　B. is making

　C. is made

　D. has made

2. The Great Wall _______ all over the worlD.

　A. has known

　B. was knowing

　C. is known

　D. knows

1. The big room _______ for meetings.

　A. are using

　B. will use

　C. can use

　D. can be used

2．用表示“减少”的动词(decrease, reduce, fall, lower等)连接“by n times”,“n times”,“n times as + 形容词或副词+as”，“by a factor of n”等，均可译 作“减少了n分之(n-1)”或“减少到n分之1”。

　因为英汉语言在使用分数方面的差异(如汉语的分母中极少使用小数点)，如果英语减少的倍数中有小数点时，则应换算成分数。

　The enterprise management expenditure this year has decreased by three times as against that of 2002.

　该企业今年的行政管理开支比2002年降低了2/3。

　The principal advantage is a four fold reduction in volume.

　主要优点是体积缩小了3/4。

　The error probability of the equipment was reduced by 2.5 times through technical innovation.

　通过技术革新该设备误差概率降低3/5。

1．用表示“减少”的动词(decrease, reduce, fall, lower等)连接“by n 或n%”，表示净减量；用系动词连接“n less(than)”表示净减量，所减数字均可照译。

　180 decreased by 90 is 90.

　180减去90等于90。

　The cost decreased by 40%.

　成本下降了40%。

　This new process used 35% less fuel.

　这种工艺少用了35%的燃料。