外壳的英文：
shell

The earth's crust is layered..
地球的外壳是分层的。

Having, resembling, or being a crust.
硬皮的，外壳的有、象或成为硬皮或外壳的

To encrust a ship's hull ith foreign matter,such as barnacles.
缠上使（船的外壳）包上外来的东西，如藤壶

Earthquakes leave scars in the earth's crust.
地震会在地球外壳上留下一些伤疤。

A pulley or a system of pulleys set in a casing.
滑轮，滑轮组安装在机械外壳中的滑轮或滑轮组

Replace by seating the assembly in the lamp housing and turning the lock ring 1/8 turn clockwise to secure.
更换组合，将组合定位于灯的外壳并顺时钟旋转锁杆1/8圈以固定。

The float is a chemical resistant polypropylene casing with a firmly bonded electrical cable protruding.
浮球采用抗化学物质腐蚀的聚丙烯外壳，配置坚固保护的电缆接头。

The goods are to be packed in tin-lined cases, and the contents of each case clearly marked on the outside.
一切货物均须用内衬马口铁或锡纸的木箱包装，且外壳必须清楚地标明其内所装物品。

The portion of the funiculus that is united to the ovule wall,commonly visible as a line or ridge on the seed coat.
脊，种脊植物珠柄与胚珠壁连接的部分，通常表现为果实外壳上的一道条纹或突起

Command shell
命令外壳

shell collecting
贝壳采集

The snail retreated into its shell.
蜗牛缩进壳里去了。

reactivation of quoted shell company
上市空壳公司恢复业务

To bombard with mortar shells.
用砂浆砌合

The shell of a snail is its skeleton.
蜗牛的壳是它的骨骼。