下文的"is composed of"为什么错了

来源：百度知道编辑：UC知道时间：2024/04/28 14:19:03

Elephants' tusks,or very large teeth growing one on either side oftheir mouths,is composed of a valuable material called ivory.
请详细说明原因

Elephants' tusks 是主语所以改用复数 are composed of

compose 有被动
be composed of =be made up of=consist of
consist才没有被动
Elephants' tusk象牙，这里是复数，当然要用are composed of

compose of 不能用于被动语态

Elephants' tusks 不能构成 ivory, 而是Elephants' tusks由ivory构成，所以要用are composed by(被动语), 绝不能用 "consist of"

Elephants' tusks 是主语所以改用复数 are composed of
我同意这个

compose of 不能用于被动语态