While he was looking for me,I saw him first.同义句

问题描述:

While he was looking for me,I saw him first.同义句
____he was looking for me,I saw him ___ before could____ me.
我填的是When,before,see对吗?
题目打错了多了一个before
____he was looking for me,I saw him ___ could____ me.

when before see