无壳的

例句：

1. 1. The crab has a hard shell that protects it from predators.
   螃蟹有硬壳，可以保护它免受捕食者的伤害。
2. 2. The tree's bark is its natural shell.
   树的树皮是它的天然外壳。
3. 3. The shell of the turtle is used for insulation.
   乌龟的壳被用来隔热。