casing

n.套；罩；匣；盒；[经](石油)套管；包装

动词case的现在分词.

An oxygen mask will come down from overhead in case of an emergency. 若发生紧急情况，头顶上会降下一只氧气面罩。

A decorative casing for a light, often of paper. 灯笼灯的装饰性外套，经常用纸制成

Such a projectile in a metal casing; a cartridge. 弹药(筒)装在金属盒中的射弹。弹药

套管

n.(玻璃)陈列柜；显示优点的东西

vt.使展示；陈列

n.砌面(外壳；装入)