【简答题】Introduce briefly the illegal file-sharing on the Internet today and the countermeasures taken by the recording industry.
【简答题】Introduce briefly the development of RFID and its possible prospects.
【简答题】PWM整流电路与二极管整流电路、晶闸管相控整流电路相比有何特点?
【简答题】Briefly introduce Buddhism.
【简答题】Introduce briefly the controversy around the wind power project in Britain.
【单选题】关于三电平整流电路和二电平整流电路下列说法正确的是( )
B.
三电平整流电路和二电平整流电路的开关状态一样多
C.
三电平整流电路整流后形成的谐波比二电平整流电路整流形成的谐波少
D.
三电平整流电路整流后形成的谐波比二电平整流电路整流形成的谐波一样