who is that speaking?为什么回答是This is...speaking

who is that speaking?为什么回答是This is...speaking Who is that speaking 回答用this 还是that Who is that speaking? This is John speaking.Who's that? hello!who is that speaking? 1.Who’s that speaking?This is Tom__________ . Is this Mr Wang speaking?Yes.___.A.I'm speaking B,Who's that 对This is Tom speaking.中的Tom怎么提问?是Who is that?还是Who is that s this is maria speaking.是否等于that is maria speaking. hello who is that speaking什么意思 英语翻译HI,this is Jack speaking.为什么要加speaking? 英语中电话用语is that speaking?回答是 yes,it is 还是she is 或者he is?this