单选题 3.I don't skate now, but I used______when I was a kid.
【正确答案】 A
【答案解析】used to“过去常常”,这是为避免重复而省略了前一句中谈到的动词:skate,只保留不定式to;但如果不定式是动词be,be不能省略,如:I’m not a diplomat now,but Iused to be.