Questions 19 to 21 are based on the conversation you have just heard.

单项选择题A．It’s a market.B．It’s a recreation center.C．It’s an algebra school.D．It’s the name of a part-time job.

单项选择题A．She broke the microphone.B．She was interrupted by a phone call during her presentation.C．She is planning to give her presentation as soon as the microphone is fixed.D．The microphone broke just as she began her presentation.