-Is John()friend of yours?-Yes.I have known him since be was
问题描述：
-Is John()friend of yours?-Yes.I have known him since be was
-Is John()friend of yours?
-Yes.I have known him since be was（）one-year-old boy.Now John is famous as（）artist.
A.a；an；an B.a；a；a C.the；an；an D.a；a；an
答
选A
第一个不能用the,是因为第一次提到用不定冠词
后面两个用an是因为元音开头.