used to do\have to do这两个动词不定式做什么成分和start to do,learn to do有什么不同呢？为什么动词不定式可以做谓语？

There ___ a museum here. A.used to B.used to do C.used to have D.used to having you do not have to change yourself,to get used used to do 造句 used to do用法 used to do用法 used to do sth. used to do sth used to do get used to do you used to have 翻译used to do used to doing be used to与have used to In the end I_hard workA.got used to do B.used to do C.got used to doing D.used to doing used to do的used的词性 You don‘t do some sports,do you?No,I ____,but now I _____climbing mountains to keep fit.A used to ；am used to B am used to ；used toC was used to；used to D use to ；used to↓No,I used to,but now I am used to climbing mountains to keep fit. tom's father______ morning exercise,but now he is ill A,is used to do B,used to doC,is used to doing D,get used to doing 2.My brothers working harder than he----------.A .used to .B .was used to C .is used to D.is used to do 说明理由 该选哪一个?-Do the Blacks lives next door to you?-No,but they ______?A.used to B.used to doC.are used to D.used todbe