It Is A和It IS An的区别.为什么是An不是A?

It Is A和It IS An的区别.为什么是An不是A? it和is的区别 this is ...和it is...的区别 it is an A ; it is A ; it is the A 哪一个是对的, it is over 和it is the end 的区别 so it is 和such it is的区别 this is it 和is this it的区别 what time is it和wen is it的区别 it is easy to be a teacher 和 it is easy being a teacher的区别. what a pity 和 it is a pity 的区别 It is 与 Is it的区别 what it is?和 what is it?有什么区别?what it is a ship?是对的,还是 what is it a ship?是对的? It is a pleasure和It is my pleasure 的区别 it is a long time和it is long time 的区别 请问It is a great… 和it is the great…的区别是什么? Is it a Korean or an English car?和Is it a Korean car or an English car?的区别Is it a Korean or an English car?和Is it a Korean car or an English car?第一个句子在Korean后有car,第二个句子没有,这两个句子都可以用吗?多一 with pleasure和It is a pleasure的区别 with pleasure和it is a pleasure的区别