帮我看一下这个英语句子Fog and haze is an serious problem needed to solve.我想知道那个needed用的对不对或者Fog and haze is an serious problem which need to solve呢？to用不用加？
问题描述：
帮我看一下这个英语句子
Fog and haze is an serious problem needed to solve.我想知道那个needed用的对不对
或者Fog and haze is an serious problem which need to solve呢？to用不用加？
答
needed和to都对的，就是全部要改成被动
needed to be solved
which needs to be solved
答
雾和霾是一个严重的问题需要解决。
答
Fog and haze is an serious problem needing to be solved.
Fog and haze is an serious problem which/that needed to be solved.