Russia and Brazil are marginal economies (which are ) supported by high prices of natural resource
问题描述：
Russia and Brazil are marginal economies (which are ) supported by high prices of natural resource
为什么这句中的which are 可以省略?
答
这里which 引导的是一个定语从句,修饰前面的先行词 marginal economies.
supported 是过去分词词.过去分词可以作后置定语来修饰限定前面的先行词,这时候相当于一个当语从句.成功又快乐!