当交流市电输入为220V时，显示器整流滤波后的输出电压为______。
A．280V
B．300V
C．310V
D．320V
参考答案：B
In somecountries， is callede quality does not really mean equal rights for all people
A that B what C which D how
胸剑联合中点至脐中的骨度分寸是()
A.4寸
B.6寸
C.8寸
D.9寸
E.12寸
