used to do,used to doing,be used to,be used to doing意思和区别

题目

used to do,used to doing,be used to,be used to doing意思和区别

答案

used to do sth是“曾经做过某事”,过去时,但to后一般加动词原形；
be used是“被使用”,被动语态,be加动词过去分词；
be used to doing sth是“习惯于做某事”,to加动名词,即do加ing.