问题
单项选择题
在生产原油量较少的油井采油时，以下哪个是人工采油法？（）
A、间歇气举
B、连续气举
C、潜油泵
D、水力活塞泵
E、螺杆泵
答案
参考答案：C
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在生产原油量较少的油井采油时，以下哪个是人工采油法？（）
A、间歇气举
B、连续气举
C、潜油泵
D、水力活塞泵
E、螺杆泵
参考答案：C
The earth moves round the sun, and the moon moves round the earth. When our part of the earth turns__46__ the sun, it is day. When our part of the earth runs away __47__ the sun, it is __48__. The sun is much __49__ than the moon. But sometimes the moon _50__ bigger than the sun, because it’s much __51_ to the earth. The sun is very bright. It gives very __52__light. The moon looks quite bright, too, but it doesn’t give any light at all. The light __53_ the moon comes from the sun. The moon looks much bigger and brighter than the stars, _54__ in fact the stars are much bigger and brighter than the moon. __55__ smaller than the moon because they are farther away from the earth.
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