Question

英译汉，不要百度上翻译器翻译出来的

1.Carbon Microphone
one of the first devices used to amplify signals was the carbon microphone (effectively a sound- controllde variable resistor).by channeling a large electric current through the compressed carbon granules in the microphone, a small sound signal could produce a much larger electric signal.The carbon microphone was extremely impotant in eraly telcommunications;analong telephones in fact work without the use of any other amplifiers.Before the invention of electronic amplifiers,mechanically coupled carbon microphones were also used as amplifiers in telephone repeaters for long distance service
2.Magnetic amplifier
A magnetic amplifier is a transformer-like device that makes use of the saturation of magnetic materials to produce amplification. It is a non-electronic electrical amplifier with no moving parts. The bandwidth of magnetic amplifiers extends to the hundreds of kilohertz.
Potating electrical machinery amplifier
3.Rotating electrical machinery amplifier
A Ward Leonard control is a rotating machine like an electrical generator that provides amplification of electrical signals by the conversion of mechanical energy to electrical energy. Changes in generator field current result in larger changes in the output current of the generator, providing gain. This classof device was used for smooth control of large motors, primarily for elevators and naval guns.
Field modulation of a very high speed AC generator was also used for some early AM radio transmissions.

Answer 1

太长！先翻译几句吧！
1.Carbon Microphone
one of the first devices used to amplify signals was the carbon microphone (effectively a sound- controllde variable resistor).by channeling a large electric current through the compressed carbon granules in the microphone, a small sound signal could produce a much larger electric signal.The carbon microphone was extremely impotant in eraly telcommunications;analong telephones in fact work without the use of any other amplifiers.Before the invention of electronic amplifiers,mechanically coupled carbon microphones were also used as amplifiers in telephone repeaters for long distance service

1、碳晶话筒
用于放大信号的一类设备之一，就是这种碳晶话筒（一种效果良好的声控可变电阻器）。由于一股大的电流经碳晶颗粒间的沟槽通过，一个很小的声音信号便可产生一个大得很多的电信号。碳晶话筒，在早期的电话通讯中是非常重要的；在实际工作中的模拟信号电话机，不采用任何其他的放大器。在发明电子放大器之前，长途电话服务也曾把机械共轭式碳晶话筒作为放大器在电话中继器中使用。