对维护炉子有利的是（）。
A.尽量减少停炉次数
B.往高温砌体上喷水冷却
C.为提高产量超高温操作
参考答案：A
They _____________ some balls, but he _____________ one. [ ]
A. have, doesn't have
B. has, don't have
C. have, doesn't has
压载水管道，不可穿过货舱和滑油舱，但可穿过饮水舱和炉水舱。
