流量低于设计要求的原因及解决办法？
参考答案：
水泵堵塞；密封环磨损过多，转数不足。
解决方法：清洗水泵及管道；更换密封环；增加水泵轴转数。
—Ouch! You hurt me!
—I am sorry. But I_____ any harm. I _____ to drive a rat out. [ ]
A. didn’t mean; tried
B. don’t mean; am trying
C. haven’t meant; tried
D. didn’t mean; was trying
手机单向通话的原因哪些。
