自动磨边机磨边加工时间过长的原因是:()。
A、砂轮长时间使用后变钝或砂轮寿命已到
B、电机损坏或机头平衡不好
C、水嘴不喷水或机头平衡不好
D、镜片未夹正或机头平衡不好
参考答案:A
—Do you have an English-Chinese dictionary?
—Yes, here you are. You can _______ it as long as you like. [ ]
A. borrow
B. lend
C. keep
诊断COPD最重要的依据是——