英语释义
1
n. a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it
2
n. device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
3
n. control consisting of a mechanical device for controlling the flow of a fluid
4
n. the entire one-piece shell of a snail and certain other molluscs