在职研究生英语（一）
下面句子的主干是哪一项？ Much of what we know about …
第 2 题单选题模拟题较易
下面句子的主干是哪一项？
Much of what we know about early human migration comes from tiny differences in the DNA that scientists collected from people living in remote mountain villages.
主干识别长难句并列结构插入语