A.直流轉(zhuǎn)換為交流B.交流轉(zhuǎn)換為直流C.高壓轉(zhuǎn)換為低壓D.低壓轉(zhuǎn)換為高壓
A.10KHz~1GHzB.1KHz~10GHzC.1KHz~1GHzD.10KHz~10GHz