1. (2020·南海模拟) Which of the following is true according to the conversation?

Hello, this is Mary speaking. Is Mr. Black there?<br />I'm sorry, but he is not here right now. Can I take a message for you?<br />That would be very nice of you. Would you please tell him to call me back before I leave London for Beijing?<br />Hello, this is Mary speaking. Is Mr. Black there?<br />I'm sorry, but he is not here right now. Can I take a message for you?<br />That would be very nice of you. Would you please tell him to call me back before I leave London for Beijing?