shell

n.

1. (贝、卵、坚果等的)壳
2. 外壳, 框架
   • After the fire, all that was left was the burned-out shell of the building.
     大火以后所剩下的就是被烧焦的建筑物的外壳了。
3. 炮弹
   • A shell exploded right beside his office.
     一颗炮弹就在他的办公室旁边爆炸了。