A、She can make a lot of friends. B、She can work more efficiently. C、She can learn mental discipline. D、She can get more familiar

W: John, have you chosen a physical education class yet for this semester?
M: No. Why?
W: You’ve got to take rock-climbing. We just had the first class and it looks like it’s going to be great.
M: You think I should take rock-climbing? You’ve got to be kidding. Besides, how can they teach rock-climbing when it’s completely flat around here?
W: That’s not important. You can’t just start climbing without any training. You have to get in shape, learn how to use the ropes, the belts, the buckles — there’s a lot of preparation first.
M: You don’t think it’s just a little bit dangerous?
W: Not if you know how to use the safety equipment, which is, by the way, pretty hi-tech. The ropes are made of elastic fabrics that stretch a little; the shoes have special plastic. You have to learn how to use all these before you do any real climbing.
M: Well, what’s the appeal? We’ll spend the whole semester studying something we don’t actually get to do?
W: We will take a climbing trip during spring break. But that’s not the point. Climbing is not the only goal. In preparing to climb you learn patience, mental discipline and you gain fantastic physical strength, especially in your hands. For the first few weeks we’re going to concentrate entirely on hand and upper body exercise.
M: All that in one sport? Maybe you are right. Since it’s not too late to join the class, maybe I will.
Questions 19 to 22 are based on the conversation you have just heard.
19. What can we learn from the conversation?
20. Why does the woman say it’s not dangerous to do rock-climbing?
21. What is one of the reasons why the woman is interested in rock-climbing?
22. What will the man probably do after the conversation?