单相半波整流电路的电压波形只有上半波。
参考答案:错
—Most of the students went to the party yesterday. It is a pity you were absent.
—I wish I . But I was terribly busy.
A.did
B.had
C.were
D.would
脏躁病的见证是()
A.喜悲伤欲哭,如神灵所作,数欠伸
B.昼日明了,暮则谵语,如见鬼状
C.常默然,欲卧不能卧,欲行不能行
D.如有神灵者,身形如和