be used to 中的to 是介词还是不定式?

题目

be used to 中的to 是介词还是不定式?

答案

be used to 中的to 有两种情况:
1.be used to doing sth习惯于做.
例如:
My father is used to smoking after a meal!
2.be used to do sth被用来做.
例如:
Pens are used to write!