造成高压电容器组渗漏油的主要原因之一是运行中温度剧烈变化。
参考答案：对
—There is a lot of wind in North China.
—Well, more trees ______ every year to stop the wind. [ ]
A. must be planted
B. can planted
C. should planted
Ethernet物理地址长度为______。
A．6bit
B．18bit
C．48bit
D．56bit
