it is unknown who中who引导什么从句

问题描述

精选答案

it is unknown who中who引导的是主句从句。

句前it在句中做形式主语。中文意思是“谁做某事不知道”例如，到目前为止，依然不知道谁救了在公园人工湖落水女孩。So far, it is stillunknown who saved the girl who fell overboard in the park artificial lake.