n.瓣膜；真空管；閥門；電子管

The valve of the heart allows the blood to pass in one direction only. 心臟的瓣膜使血液只能朝一個方向流動

We need a valve detector. 我們需要個真空管檢波器。

The pump sucks air out (of the vessel) through this valve. 這臺泵通過這個閥門把(容器中的)空氣抽出。

We need an eye bolt to fit this valve. 我們需要一個有眼螺栓來固定這個閥門。

Have you turned off the water valve? 你關(guān)掉水閥了嗎？

John Ambrose Fleming invents the two-element "Fleming Valve". 約翰.

雙殼類,蚌類