名词

1. 阀;活门
A valve is a device attached to a pipe or a tube which controls the flow of air or liquid through the pipe or tube.

2. （心脏的）瓣，瓣膜
A valve is a small piece of tissue in your heart or in a vein which controls the flow of blood and keeps it flowing in one direction only.

3. see also: safety valve

1. one of the paired hinged shells of certain molluscs and of brachiopods

2. the entire one-piece shell of a snail and certain other molluscs

3. control consisting of a mechanical device for controlling the flow of a fluid

4. device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone

5. a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it