tusker

例句：

1. 1.The tusker is a large marine mammal that lives in the Arctic.
   驼鹿是一种生活在北极的大型海洋哺乳动物。
2. 2.The seal is a small sea mammal that lives in cold waters.
   海豹是一种生活在寒冷水域的小海洋哺乳动物。
3. 3.The tusker's tusks are used for their valuable ivory.
   驼鹿的象牙被用来制作贵重的工艺品。