tusks

例句：

1. 1. The elephant's tusk wasthe most valuable part of the animal.
   大象的象牙是动物最有价值的部分。
2. 2. Theivory trade is illegal and hasbeen banned in many countries.
   象牙贸易是非法的，许多国家已经禁止了。
3. 3.The conservationists are working hard to protectthese endangered species.
   保护工作者正在努力保护这些濒危物种。