传声器按时间发展的顺序依次是

A、压电陶瓷式、电磁动圈式、驻极体式
B、电磁动圈式、驻极体式、压电陶瓷式
C、电磁动圈式、压电陶瓷式、驻极体式
D、驻极体式、电磁动圈式、压电陶瓷式;
E、压电陶瓷式、驻极体式、电磁动圈式。
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正确答案:

B

答案解析:

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事故处理“四不放过”原则是什么?

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