问题
选择题
You shouldn’t have the machines ______ all the while. You ought to have them ______ now and then.
A．run; repair
B．running; repairing
C．run; repaired
D．running; repaired
答案
答案：D
考查非谓语动词。句意：你不应该让机器一直运转。你应该不时地把他们修理一下。结合语境可前正在进行的动作伴随性动作，下文描述的是被动动作，故选D。