自锁的作用是防止两个接触器的主触头同时闭合,造成电源短路事故
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兆欧表必须水平放置于平稳牢固的地方,以免在摇动时因抖动和倾斜产生测量误差。
A. 对
B. 错
在检修电动机控制线路时,不能随意更改线路和带电触摸电器元件。
A. 对
B. 错
It's very kind _______ you to deliver our order on Sunday.
A. for
B. of
C. to
D. with
It's very important _______ us to get the order to our customers.
A. for
B. of
C. to
D. with