中国大学MOOC: These transistor（晶体管） circuits can amplify（放大） voltage signals with minimum waveform distortion（波形失真）. 下划线介词短语充当_______。
举一反三
- These transistor circuits can amplify voltage signals with minimum waveform distortion. 下划线介词短语充当_______。
- 中国大学MOOC: The resistance of the load （负载）is too high for the amplifier（放大器）. 前后两个下划线介词短语分别充当_______。
- The sound-carrying medium may be matter in any state. 下划线介词短语充当_______。
- 中国大学MOOC: Alternating current（交流电） as a source of power has certain advantages over direct current（直流电）. 前后两个下划线介词短语分别充当_______。
- The resistance of the load is too high for the amplifier. 前后两个下划线介词短语分别充当_______。