hello!are you mike?(改为电话交际用语)

英语打电话问对方是谁的完整说法是 It that Mike speaking over there (那头说话的是麦克吗)?，who is that speaking over there (那头说话的是谁呀)?，简单地说就是 It that Mike speaking? 或 It that Mike? , who is that speaking? 或 whois that?
同样，如果有人敲门，你可以问 Who is that knocking? / Who is that?