不对啊!
可以改为：
The city is 【what he visits.表语从句】
or
The city is 【where he goes.表语从句】
My idea is that we should go out at once.
祝你开心如意!用which 为什么不对呢？谢谢！which，哪一个/些，在所给的句子中作定语，所表达的意思不对。当然，你给的句子也可以变成定语从句：The city is the one【(that) he visits.定语从句】。The city is whichhe visits这句话 对吗?麻烦你 老师!不对。可以修改为：This is 【what he visits表语从句】.这就是他游览的（什么）地方。或This is the place 【which /that he visits.定语从句】这就是他游览的地方。