例句與造句

1. It is composed of four parts : dc ( direct current ) power supply , resonance charging and polarity reverse unit , electric relay control unit and computer control unit
   它主要由四部分組成：三相整流直流電源，諧振充電及電壓反向單元，繼電器控制單元，計(jì)算機(jī)控制單元。
2. It's difficult to find polarity reverser in a sentence. 用polarity reverser造句挺難的