单支红色发光二极管表示电源已接通。A single red LED shows that the power is switched on.按这种方式使用的二极管叫做整流管.A diode used in this manner is called a rectifier.二极管早已作为常规器件应用于多种电路中.The diode is used routinely in many kinds of electronic circuit...
这首曲子我弹不来 -- 降半音音符太多了.I can't play this - there are too many flats.我误读了乐谱上的b降半音音符.I misread the b flat note on the sheet.有很多升半音、降半音难度很大的钢琴曲.A difficult piano piece full of sharps and flats....