请问是an eleven-year-old boy还是an eleven-year old

请问是an eleven-year-old boy还是an eleven-year old a eleven-year-old还是an eleven-year-old 当an eleven-year-old girl中eleven是数字11时用a还是an当an eleven-year-old girl中eleven是数字11时前面用a还是an an eleven year old 和 an eleven-year-old用哪个?为什么 Maomao is an eleven-year old boy.的意思 为什么用an eleven-year-old boy?eleven开头发音不是辅音吗? eleven前是a还是an She is an eleven year old student.(不改变句意啊）根据这句句子改：The___student is eleven ___old. eleven-year-olds跟eleven-year-old的音标分别是什么?谢eleven-year-olds跟eleven-year-old这是我在英语书上看到的,烦请哪位知情人士告知音标. Bob is (a) eleven-year-old boy.为什么用a不用an? 请问是he only has an 8-year-old son还是he has only an 8-year-old son? Don’t complain to him.You know he is _____ boy.A.a three-years-old B.an eleven years oldC.an eleven-year-old D.only three year old 为啥? I ____ (是）eleven now.I____ （是）ten last year. I was eleven last year.对eleven进行提问 I was eleven last year. 对eleven进行提问 地球OL是神马 请问Skate OL什么意思! I am eleven year old.（改错）