This is a good way of finding the exact source of trouble in a motor-car engine which sounds as if it is wrong and yet gives no information of where the trouble is.

• 如果汽车引擎的声音听起来似乎不大对劲却又不知道毛病出在什么地方，那么上面的方法就是一种能够准确地找到故障原因的好方法。