在电风扇、电熨斗、电磁起重机、扬声器和动圈式话筒中，利用“电磁感应原理”工作的有______；利用“通电导体在磁场中要受到力的作用原理”工作的有______．
（1）电风扇里主要部件是电动机，它是通电能转动的机器，即利用通电导线在磁场中受力的作用；
（2）电熨斗是利用电流的热效应的原理工作的；
（3）电磁起重机是利用电流的磁效应的原理工作的；
（4）扬声器是将电信号转化成声信号，即其内部有一个电磁铁，当其内部通过变化的电流时，电磁铁的磁性会有规律的变化，从而吸引膜片有规律的振动，进而产生声音；
（5）动圈式话筒是声信号转化为电信号的机器，即是利用电磁感应现象的原理制成的；
故答案为：动圈式话筒，电风扇．
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| The three superstars were arriving at the airport and a large crowd of young people had already gathered there to welcome them.The police found it 1 to keep order after the plane landed and the performers 2 . They smiled and waved cheerfully at everybody.Dressed in the same pink shirts and light blue trousers, with long hair and musical instruments over their shoulders, they all looked 3 . Although there were many policemen 4 , the Blare were not able to get to their waiting car 5 at all. Word spread that they had composed a new song which would be 6 when they performed at the concert that evening.They were now 7 with loud cries of" Play your new song! Play your new song!" When the stars prepared to sing as the 8 for getting away, even the policemen looked 9 , too. The tans settled down and listened to the first 10 of the new song.Once it was over, everyone started jumping, clapping and shouting 11 . Several young women even fainted (昏倒) with excitement and were carried away immediately by the 12 standing by. The fans were greedy for more, 13 a repeat performance.Once again, the performers had no choice but to 14 , but when they were asked for still another song, they cheerfully but firmly refused.Closely 15 by the policemen, they walked towards their car some distance 16 . The fans pushed forward, but the policemen, 17 arm, prevented anyone getting trough. It took the stars quite a long time to reach their 18 ! Finally, however, they all got in and were just about to leave when a young woman, who had somehow 19 to gel past the policemen, jumped onto the roof of the car.She shouted loudly and crazily as two policemen dragged her away and the car started to move very slowly through the 20 crowd.She had just wanted to have a photo taken with the stars! | ||||
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