在英语电话中询问对方是谁，常用的表达有：
"Who is that？"
"Who is this？"
"May I ask who's on the line？"
"Can I speak with you？"
"Who am I speaking with？"
回答时，通常使用：
"This is [Your Name]."
"Hello, this is [Your Name]."
"I am [Your Name], how can I help you？"
请根据具体情况选择合适的问法和回答