Question

They believe there is no such thing as separate but equal

They believe there is no such thing as separate but equal.这个句子的 as ,but是什么用法啊，there is no such thing as separate but equal又是什么意思。

Answer 1

They believe there is no such thing as separate but equal
no such thing as 是不存在像什么之类的事物，but 这里不是no such as 的转折，而是 thing 的定语， 即 as separate but equal 修饰thing这个定语。
翻译：他们认为没有这种独立存在而又相互平等的事情。