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？

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？ Tim is ____boy.He can say a few words.A.an one-year-old B.a one-year-old C.an one-year oldD.a one-year old mr.green has ___ one-year-old son,doesn't he yes and he also has ___8-year-old daughtera .a ab an ac a and an an 选哪个,怎么选的 The dog is one .选择A year B years old C old D year old 是a one-year-old boy还是an one-year-old boy My son is eight year old.改错 选择1.my brothers is ( )than me A one old year B one year old C one year older D one years old my son,a doctor at a hospital,finished a physocal exam o______a six year old boy. Tom is a 15-year-old son of a rich farm owner one－year-old前面用an还是a a one-year-old boy为什么不是an He is () one-year-old boy.A anB aC the Tom has( ) one-year-old brotherA a,B an the baby is one and a half _____ (year)old one day,i was at the ,grocery store with my seve-year-old son.as we walked through完型 she looks for a school bag for her 7-year-old son. - Though Mike is ( )boy,he can say many words.--How cleverA.an-one-year-old B.a one-year-old C.an one-year old D.a one-year old i have a five year old son and 18 month old dauuhter at christmas time i wanted them