Most young people enjoy physical activities, walking, cycling, football, or mountaineering. These who have a passion【21】climbing high and difficult mountains are often looked upon with astonishment. Why are men and women【22】to suffer cold and hardship, and to【23】on high mountains? This astonishment is caused, probably, by the difference between mountaineering and other forms of activities【24】which men give their leisure. There are no man-made rules, as there are for【25】as golf and football. There are, of course, rules of different kinds which it would be dangerous to ignore, but it is this freedom from man-made rules【26】makes mountaineering attractive to many people. Those who climb mountains are free to their own methods. If we【27】mountaineering with other more familiar sports, we might think that one big difference is that mountaineering is not a 'team work'. However, it is only our misunderstanding. There are, in fact, no 'matches'【28】'teams' of climbers, but when climbers are on a rock face linked by a rope on which their lives may【29】, obviously, there is teamwork. A mountain climber knows that he may have to fight with natural【30】that are stronger and more powerful than man. His sport requires high mental and【31】qualities. A mountain climber【32】to improve on skill year after year. A skier is probably past his best by the age of thirty, and most international tennis champions【33】in their early twenties. But it is not【34】for men of fifty or sixty to climb the highest mountains in the Alps. They may take more【35】than younger men, but they probably climb more skill and less waste of effort, and they certainly experience equal enjoyment. (41)