ltisnotyetknowwhereshehasgone.中lt的用法

lt is not yet know where she has gone.中lt的用法

这里的 it 是形式主语，真正的主要是从句 where she has gone。
可以把上面的句子改写成：
where she has gone is not yet known.

lt is not yet know where she has gone. It是形式主语，真正的主语是“where she has gone” 再看看别人怎么说的。