题干


You shouldn’t have the machines ______ all the while. You ought to have them ______ now and then.
A.run; repairB.running; repairing C.run; repairedD.running; repaired
上一题 下一题 0.85难度 单项选择 更新时间:2010-06-08 11:06:24

答案(点此获取答案解析)