often thousands of miles away这个插入语是定语从句还是同位语从句

问题描述

Beyond simply supporting a dazzling variety of life, we have to remember that vast forests like these, often thousands of miles away, are crucial to every one of us, not least because they help to stabilise the climate and maintain the water cycle.

请问：often thousands of miles away 这个插入语是定语从句还是同位语从句？

老师答疑

刘老师：

often thousands of miles away 既不是“插入语”，也不是“同位语”，而是定语，修饰vast forests like these，作用相当于一个非限制性定语从句：which are often thousands of miles away。

你这个问法，概念有点混乱。既然你叫它“插入语”了，怎么还定语从句和同位语从句？

【插入语】不具体修饰句子中的某个成分。

【同位语】两个词语之间，存在着互为“同位关系”。森林 = 数千英里？