Good Morning, This is David, Who is speaking?
早上好，我是大卫，请问您是谁？
This is Tom speaking. Who is that (speaking)?
我是汤姆，你是谁？
This is John speaking, who is that speaking?
我是约翰，您是哪位？
This is Frank speaking. May I ask who is calling?
我是弗兰克。请问您是哪位？
This is Frank speaking. May I ask who is calling?
我是弗兰克。请问您是哪位？
应用推荐