选择适当的词或短语并用其正确形式填空（5分）

1. Lacking necessary money, the small companies ________ one by one during the economic crisis two years ago.

2. He is delighted ________ his driving test and now can drive a car on his own.

3. The magazine is meant ________ white-collar working women in their twenties and thirties.

4. The incident(事件) ________ a chain(系列) of events which led to the outbreak of World War II.

5. It is easy to make a promise, but difficult to ______ it ______.

6. We watched the street lights ________ one after another at dawn.

7. Various factors ________ the downfall of the government.

8. Women only ________ 30 percent of the workforce in that factory.

9. We should avoid ________ this kind of trick again.

10. At the present speed, the world’s oil supply will ________ soon.

国家标准规定的表面粗糙度的评定参数中Ra代表（）。

A、微观不平度十点高度

B、轮廓最大高度

C、表面不平度

D、轮廓算术平均偏差