a device which opens and closes to control the flow of liquids or gases , or a similar structure in the heart and the veins , which controls the flow of blood
发音
例句
1. The exhaust valve on my car has burnt out. 我汽车上的排气阀烧掉了。 2. The connecting rod may drive a valve stem directly. 连杆可以直接带动阀门的把柄。