B级电子计算机供电电源稳态频率偏移范围在-1~+1Hz。()
参考答案:错
Whenever you are in trouble ,don’t hesitate _____us for help.
A.in asking
B.with asking
C.to ask
D.to asking
下列设备工作时,将化学能转化为热能的是( )
A.A
B.B
C.C
D.D