不确定或未知的人，一律用it 顺便说一下it作代词的用法。1代替this, that.如 -- What’s this/that?– It’s a map.2代替上文提到的单数事物。如 My pen is lost, and I can’t find it. 注：区别it和one：it是代替特指的事物, one是代替泛指的事物。如 My pen is lost. Have you seen it? (特指)/My pen is lost. Do you have one? (泛指)3代替未知的人。如 Is it a man or a woman?4代替小孩，尤指婴儿。如 She had a baby ye
