[单项选择]Questions 19 to 21 are based on the conversation you have just heard. A. It plans to send a probe to explore the moon. B. It’s NASA’s most expensive project so far. C. It’s an ambitious project. D. It’s involved in the construction of the American space station.
参考答案:C 答案解析:[听力原文]19-21 W: What do you do for a living, Frank M: I am an aerospace engineer. I have been