Most of us lead unhealthy lives; we spend far too much sitting down. If in addition we are careless about our diets, our bodies soon become loose and fatty and our systems slowmoving. There are some aspects(方面) of our unhealthy lives that we cannot avoid. I am thinking of such features of modern city life as pollution, noise, rushed meals and stress. But keeping fit is a way to reduce the effects of these evils. The usual suggestion to a person who is looking for a way to keep fit is to take up some sport or other. While it is true that every weekend you will find people playing football and hockey in the local park, they are outnumbered a hundred to one by the people who are simply watching them. For those who do not particularly enjoy competitive sports — and it is especially difficult to do so if you are not good at them — there are such separate activities as cycling, walking, jogging and swimming. What often happens though is that you do them in such a leisurely way, so slowly, that it is doubtful if you are doing yourself much good, except for the fact that you have at least managed to get up out of your armchair. Even after you have found a way for keeping in shape, through sport or gymnastics, you are still only half way to good health, because, according to the experts, you must also the art of complete mental and physical relaxation(放松). It has to do with deep breathing, emptying your mind of all thoughts, meditation, and so on. Yoga, as practiced in the West, is the most widely known and popular of the systems for achieving the necessary state of relaxation. It seems ironical (讽刺性的), though, that as our lives have improved in a material sense we have found it increasingly necessary to go back to forms of activityphysical effort on the one hand and relaxation on the other — which were the natural way of life of our forefathers. 12. Pollution, noise and stress are examples of _____. A. causes of unfitness B. bad features of living in towns C. the things we can completely do away with D. unavoidable things in town 13. We don’t get much out of separate sports because we _____. A. don’t do them very often B. don’t do them actively enough C. find it hard to get out of our armchairs D. don’t find them interesting 14. To be healthy we must _____. A. keep fit and active                                      B. keep fit and learn to relax C. be active and practise Yoga                               D. have a sound mind 15. Our forefathers were healthy because______. A. their way of life closely connected with both exercise and relaxation B. they were careful to get plenty of fresh air C. they spent most of the time out of doors D. their environment was not polluted