蟹穴

例句：

1. 1. The crab's shell is a marvel of nature.
   螃蟹的壳是大自然的奇迹。
2. 2. He found the crab's shell in the sand.
   他在沙子里发现了螃蟹的壳。
3. 3. The crab's shell was a valuable artifact.
   螃蟹的壳是一件珍贵的文物。