关于use的用法used to do sthbe used to do sthbe used to doing sthu

1 过去常常做某事I used to make friends with others
2 被用来做某事the words are used to hurt firls
3 习惯做某事I am used to making jokes
1=4
5 当作 I use this as my pen
6用..来做I use it to cut the wood