A：Hello!Who is that?
B:Hello!This is B .May I speak to .?
A:Sorry,he/she isn't here.Can I take a message for you?
B:That's very kind of you,please tell .that .
B:Hello!May I speak to A
A:Speaking./This is A speaking.
切记,在电话中切不可用日常生活中的那种问候方式,比如说：“Who are you?”或“I am ...”这样是很不礼貌的.