50Hz的交流电,其周期为()。
A、50ms
B、20ms
C、12ms
D、120ms
参考答案:B
-The bike is in the way, could you please _ it away?
-Sorry , I’ll do it _ . [ ]
A. take ; right here
B. put; at once
C. move ; right away
D. send ; at first
《危险货物品名表))(GB12268-2005)中所列的货物,均必须按危险货物进行运输。