so的.例句：
1、There wasn't much traffic so we made good progress.
来往车辆不多，所以我们开得很快。
2、I've got my own room so I'm well off.
我有自己的房间，所以还不错。
3、 It wasn't so good as last time.
这次不如上次好。
4、There are so many different makes to choose from.
有很多不同的型号可供选择。
5、Why do you make things so difficult for yourself?
你为什么这样跟自己过不去？