It is an"u "and that is a "s"中的an和a是否填对?

问题描述:

It is an"u "and that is a "s"中的an和a是否填对?

It is an“u”and that is a “s”
两个都用反了
u虽然是元音字母,但读音是辅音开头,所以用a
而s虽然是辅音字母,但读音元音是开头,所以用an