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【单选题】
指出下列命题哪个是正确的:
A.
若AB=Φ,则 A B ≠Φ
B.
若若AB=Φ,则 A B = Φ
C.
若A⊂B 则 B ⊂ A
D.
若 A⊂B,则 A∪B =A
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参考答案:
举一反三
【单选题】三相异步电动机能耗制动时定子绕组在切断三相交流电源后()。
A.
通入交流电
B.
通入直流电
C.
先通入直流电、后通入交流电
D.
先通入交流电、后通入直流电
【简答题】Music festivals in Europe Visiting a festival abroad can be a great reason to travel and a way to experience different cultures. These days there is such a number of choices that it’s possible to spen...
【简答题】人类和动物 跨步的目的只有两个,请简述其跨步的目的
【简答题】A Music festivals in Europe Visiting a festival abroad can be a great reason to travel and a way to experience different cultures. These days there is such a number of choices that it’s possible to sp...
【单选题】Which country is the number 1 on the list of an estimate of the number of Jews murdered between 1939 and 1945?
A.
Holland
B.
Poland
C.
Hungary
D.
Germany
【判断题】职业生涯目标要明确,措施要具体,落实也要有制定具体的规划
A.
正确
B.
错误
【简答题】Translate the following sentences into Chinese. 1.The hydrolysis products were yzed using TLC incorporating Silica gel 60 plates (Merck, Darmstadt, Germany) and were developed by a solvent system ...
【简答题】能耗制动:(动能制动)在电动机切断交流电源后,立即在定子绕组的任意通入 电
【简答题】在电动机切断交流电源后,通过立即在定子绕组的任意两相中通入 ,以消耗转子惯性运转的 来进行制动的,所以称为能耗制动,又称 。其中单向启动能耗制动常用于 以下小容量电动机。
【简答题】交流异步电动机能耗制动时,在切断交流电后,需在定子绕组中通入 [填空1] 电机才能进行能耗制动。A. 直流
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