地网中经常要用到各种类型的体，按摆放方向可以分为（）。
A. 埋地接地体
B. 垂直接地体
C. 水平接地体
查看答案
在夹紧薄壁工件时，要尽量夹在工件刚性好的部位。
A. 正确
B. 错误
Why were the French troops in Canada defeated by the British during the Seven Years.War?（）
A. Because they were not used to the weather in Canada.
Because they did not get support from the local people.
C. Because they did not receive the supplies they needed so badly.
D. Because the British had larger and better settlements in Canada.
用无水氯化钙作干燥剂是，适用于（）类有机物的干燥。
A. 醇、酚
B. 胺、酰胺
C. 醛、酮
D. 烃、醚
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