为什么用an eleven-year-old boy?eleven开头发音不是辅音吗?

an eleven year old 和 an eleven-year-old用哪个?为什么 为什么用an eleven-year-old boy?eleven开头发音不是辅音吗? Bob is (a) eleven-year-old boy.为什么用a不用an? 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 请问是an eleven-year-old boy还是an eleven-year old Maomao is an eleven-year old boy.的意思 don't talk to simon like that .heis only 【】eleven-year-old boyA.a B.an C.the D.不填为什么这么选翻译thanks 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. the year 2011 should be read the year ( ) a.twenty eleven a.two thousand and eleven b.twenty eleven选B.为什么? the year 2011 should be read the year ( ) a.twenty eleven a.two thousand and eleven b.twenty eleven选B,为什么? Lily is eleven years old this year.用next year 替换this year改写句子 eleven和effect前面冠词用a还是an It's eleven o'clock.(用what提问) 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 was eleven last year.对eleven进行提问 I was eleven last year. 对eleven进行提问 a one-year-old son为什么冠词是a不是an ?急求!one的o不是原因字母么？