Who's this用this is回答还是it is回答

Who's this用this is回答还是it is回答 Phone #对不?为什么不用at?what's this in English?怎么回答?有this is的形式么?还有who's this?是不是用it's的回答而不用this is? Who's this?该怎么回答? what's this in English?怎么回答?可以用this 还是只能用It is 还有Who is that?是要用he/she还是it回答 Who is that speaking 回答用this 还是that Who is this?一般怎么回答? 改错Who's book is this?（） 改错 Who's book is this? This is Ben( ).Who's that,please Who's that boy 用什么回答?It is …还是 He is…Is this your mother 用什么回答?yes,she is 还是 yes ,it is -()?-This is Chen Jie spaking.A Who are youB Who's this C Who's that Who's this? who's this boy? Who's this?... who is this 或Who is that的回答可以用she is 或he is吗还是必须用this is 或that is who is that speaking?为什么回答是This is...speaking Who is this man? who is this man?