used to do 表示过去常常做某事，而现在往往不做了
i used to get up early in the morning when i was still a hight school student.
be used to doing 表示习惯于做某事
i am used to eating rice now.
be used to do表示...被用来做某事
Pig Stem Cells to Be Used to Grow Human Organs?
这些应该是正确的吧？【好吧 承认自己有点烦了 以前基础差。。。
