谢谢牙仙一贯的的勤于动脑！！补课中有例句。
beautifulwind
2011-10-19 14:39:41
( reads)
谢谢牙仙的一贯的勤于动脑！
补课中有例句：
(1) “have to, had better, used to”要用下列方式反问：
They used to smoke, didn't / usedn't they?
所以，你这句话可以是：
He used to be a sailor, didn't/usedn't he?
全国牙防组
2011-10-19 15:43:21谢谢回答！不过