学员HQ9EDU09060: 老师，请问When，while，as，前后应该加的时态是什么？
老师回复: (continued)
as 常用于:
1 表书两个发展变化中的情况:
As you grow older, you'll know better and better about yourself.
2 表示"一边……一边……“：
They talked happily as they walked along the river.
3 表示随着短暂动作的发生，另一行为伴随发生：
My cap was blown away as I sat down.
