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
used to do sth :过去常常做某事 be used to do sth :被用来做某事 be used to doing sth :习惯做某事 use for use as use to不可以单独用,常用于被动语态中,分别表示被用来做某事(接v-ing)、被作为……用来、被用来做某事(接不定式)