人们还为了象牙而杀害大象。

People also kill elephants for their ivory.

我们必须保护树木，不要购买象牙制品。

We must save the trees and not buy things made of ivory.

这把梳子是用象牙做的。

This comb is made of ivory.

她的项链是用象牙制品做的。

Her necklace is made of ivory.

象牙雕刻是一门古老的艺术。

Ivory carving is an ancient art.