用a,an,the填空:There is ____"s" in "sofa"

问题描述:

用a,an,the填空:There is ____"s" in "sofa"
回答并说明理由

There is _an_"s" in "sofa"
有一个字母S在单词sofa里
s的发音是元音固用an,不用a,s不是特指的也不能用The