---hello,is this Mr.liu speaking?----(yes,who is that?that怎么

---hello,is this Mr.liu speaking?----(yes,who is that?that怎么 Hello,is that Mr.Black speaking?Yes,who's that? Hello!is that liu Tao?yes,_______Liu Tao speaking hello!who is that speaking? Is this Mr Wang speaking?Yes.___.A.I'm speaking B,Who's that C:Hello!A:Hello!Is that Mr Wu? C:Yes.Who is it,please?A:This Hello!Is that Mr Wang speaking?--Yes,____________?( Hello!Is that Mr.Wang speaking?Yes.___ Hello,is that Liu Tao?Yes,＿. hello who is that speaking什么意思 This is John speaking.Who's that? Who is that speaking?