听力原文：M: I have been studying too much and need a change. So I have just made plans to go away during January break.
W: Really? Where are you going?
M: I'm planning to visit New Mexico.
W: My sister and I had the vacation there last year and we had a great time.
M: Did you get into Albuquerque?
W: Sure. Whenever we went skating.
M: Is it far from the mountains?
W: Not at all. Even though Albuquerque is on a high flat plateau, there are even higher mountains near it. Just half an hour away from the city there is a snow-covered slope.
M: Well. As the mountains are just thirty minutes away, I guess I should take my ice skate and my skis.
W: Definitely.
M: I heard that the weather there was great.
W: It is 'No humidity' but with moderate temperatures, but you do need to be careful about high altitude.
M: What should I do about that?
W: Oh, just take it easy for a few days. Don't go hiking up the mountains or exercise too vigorously. Just do everything gradually.
M: I'm sure I will be fine. And I will let you know all about my trip when I come back.
What is the main purpose of the man's trip?
A．To improve his skating techniques.
B．To climb mountains.
C．To take a vacation.
D．To learn to ski.