Who was it?哪位? /谁呀?

I heard the phone ring. Who was it?

我听见电话响了，是谁呀?

It was a salesman from an insurance company.

保险公司的推销员。

Who is this?哪位?

Hi，it’s Tracey. Who is this?

你好，我是特雷西，你是谁?

It’s Steve. Don’t you recognize my voice?

我是史蒂夫，听不出我的声音吗?