外壳的

例句：

1. 1. The turtle has a hard shell to protect its soft body.
   乌龟有硬壳来保护它的柔软身体。
2. 2. The crab has a tough shell that helps it to walk on land.
   螃蟹有坚硬的壳，帮助它行走在陆地上。
3. 3. The egg is encased in a hard shell.
   蛋被一个坚硬的壳包裹着。