这是单词constituent的一个例句,以示意它有"成分"的意思.
which指的是constituent,
it指的是"a mixture,substance,or system".对，我是看到这个单词constituent的例句解释，然后看到这个不是很明朗。which 的先行词是constituent？如果which 的先行词是constituent,是不是该这么说：A constituent of a mixture, substance, or system from which it is formed is one of the things .which的先行词在语法上是one of the things, 从句子意思的角度讲它们都是指被解释的词constituent.