“an old man ” 为什么用“an”

“an old man ” 为什么用“an” 是a old man还是an old man?如果是an的话,那为什么university是用a呢? an onehundred-year-old man用a还是an Mr Wang is an man.A.28-year-old B.80-year-old 为什么 Next door to ours _________,who has just return from abroad.A.where lives an old man B.where does the oldman liveC.lives an old man D.does an old man live答案是C请问A 为什么错 AN OLD MAN 翻译 A girl helped an old man,and the old man was excited译成中文 being an old man now 和having been an old man now 选择题选项（ ）,he prefers a quiet life.a.being an old man now b.having been an old man now为什么不能选b.是b选项本身有问题吗?还是什么? 16.The door opened and there ________.A.enters an old man B.entered an old man C.did an old man next door to ours_____,who is no less than eighty选择题A.that lives an old man B.lives an old ma为什么这样选呢? 用冠词a,an,the填空,不需要处画×（）old man in ()car is () old teacher. There is an old man living _in a _house.用alone 与lonely填 Once there lived an old man in a twon. There is an old man in a house There an old man sat,smoking a pipe分析下 please take a s() tom said to an old man 谚语An old man never wants a tube to an old man lived in a certain part of london