though a number of descents have been made,much of it still remains to be ex much of it错了！！

Question

如题所述

Answer 1

Though a number of descents have been made,much of it still remains to be explored

人们多次进入洞内探险，但至今尚有不少东西有待勘探。

没错啊 这里的it 不是指代 从句中得descents 而是指代前文中的洞穴 所以用it 而不是them
望采纳！