剩余电流动作保护器的安装场所应()、(),并注意防潮、防尘、防震动和避免日晒。
参考答案:无爆炸危险;无腐蚀性气体
Your mother, however, ____ say that to us that day.
A.does
B.did
C.is doing
D.was doing
重介质旋流器溢流口直径越大,实际分离密度越大,精煤产率()
A、越大
B、越小
C、不变