in theirs twenties 的用法 我觉的用their才对.是题出错了吗?

in theirs twenties 的用法 我觉的用their才对.是题出错了吗? in his twenties 与in his early twenties 的区别 in the twenties和in one's twenties所表达的意思有什么区别. 一句英语的语法理解in one's twenties or something 和 in one's twenties的区别 In his twenties 这句话 twenties为什么是复数啊? in ones early twenties 与 in ones late twenties 有什么区别?（ones是某某人的意思） in one's early twenties和in one's late twenties意思是一样的吗?为什么一个是early,一个是late? in her early twenties,in her late twenties,in hin her early twenties,in her late twenties,in her early teens,in her late teens in the nineteen twenties ,翻译成中文. ( )of the students in John's class are in ( )A.one-half,the twenties B.Half ,the twenties C.half,their twenties D.A half ,their twenties He worked in his twenties.in his twenties有什么道理? Emily is in her twenties对in her twenties划线提问 in of at和age之间的用法.如of sb's own age,in their twenties等等. In her twenties 这句话中为什么用twenties 而不是twenty ? 在他20岁的时候可以说：in his twenties.“in his twenties”怎样理解?那么说：在我一岁的时候、在她五岁的时候该怎么说? It was said that Tim was already very famous as a dancer _______ in the USA when he was only ten.A.in twenties B.of twenty C.in his twenties D.in the twenties我本来选的是C 但是后面的参考答案是D 不理解 还有 这句话的意思也 在他20岁那年用英语怎么说?就是用这样的句型:when he was in his twenties.为什么twenties要用复数?有没有固定句型? I have served army___when I was__. A.in the 1980's,in the twenties B.in the 1980's,in my twenties在某人20岁, 到底是in the twenties还是 in my twenties?谢谢各位!