三相电源的相序有正相序和逆相序之分，表示为U-V-W和（）
A、V-W-U
B、W-V-U
C、U-W-V
D、V-U-W
参考答案：C
-- What a day! It's mining again. We can't go hiking tomorrow.
-- Don' t worry. It won't __________ long.
A．drop
B．rain
C．go
D．last
报表眉的内容只在报表的 【10】 打印输出。
