自然环境与环保（19-28）

19. Fight over Fox-hunting 猎狐引发的冲突
① Foxes and farmers have never got on well.These small dog-like animals have long been accused of killing farm animals.They are officially classified as harmful and farmers try to keep their numbers down by shooting or poisoning them.
② Farmers can also call on the services of their local hunt to control the fox population.Hunting consists of pursuing a fox across the countryside,with a group of specially trained dogs,followed by men and women riding horses.When the dogs eventually catch the fox,they kill it or a hunter shoots it.
③ People who take part in hunting think of it as a sport;they wear a special uniform of red coats and white trousers,and follow strict codes of behavior.But owning a horse and hunting regularly is expensive,so most hunters are healthy.
④ It is estimated that up to 100,000 people watch or take part in fox hunting.But over the last  couple of decades the numbers of people opposed to fox-hunting,because they think it is brutal,has risen sharply .Nowadays it is rare for a hunt saboteurs.Sometimes these incidents lead to violence,but mostly saboteurs interfere with the hunt by misleading riders and disturbing the trail of the fox's smell,which the dogs follow.
⑤ Noisy confrontation between hunters and saboteurs have become so common that they are almost as much a part of hunting as the pursuit of foxes itself.But this year supporters of fox hunting face a much bigger threat to their sport.A Labour Party member of the Parliament is trying to get Parliament to approve a new law which will make the hunting of wild animals with dogs illegal.

20. Dog,Man's Best Friend 狗,人类最好的朋友
①The dogs has always been considered man's best friend.Always noted for being particularly faithful in watching over children,he also has his place by the fireside,in the crowd pasture,on the sheep rangr,and beside the hunter in forest or the blind.He is easy to train,works hard,and often performs astonishing tricks.And in the frozen polar regions he was once the principal motive power,before being largely displaced by the plane and helicopter.
② Because he howls and whines in the presence of approaching death,the dog was once thought to have supernatural powers and believed to be capable of seeing gods and ghosts invisible to men.Actually,the basis for these beliefs lies in the dog's sensitivity to people's feelings and his superior hearing ability and sense of smell,which enable him to detect signs hidden from human observation.His record of saving lives is outstanding,for he often gives warning of fire and other dangers not noticed by his master.
③ The dog's major contribution,however,has been to medical research.Both his diet and his structure are comparable to those of the human being,and so he has been the subject of countless demonstrations and experiments.Open-heart surgery has been made possible largely because of the dog.But his sacrifices have repaid his own species as well by safeguarding it from rabies,distemper,and other diseases.

21 Survival of Desert Life 沙漠生命的延续
① Some desert animals can survive the very strong summer heat and dryness because they have very unusual characteristics.The camel,for example,can hear an increase in the temperature of its body and its blood of 9℃.In addition,it can drink an enormous amount of water in its red blood cells and other parts of its body to supply its needs for two weeks or more.The kangaroo rat,on the other hand,obtains all the water it needs from water that it produces during respiration.However,most animals need to maintain a fairly constant body temperature,and will die If it rises more than 5℃.Therefore,they must find some way to avoid the strong sun rays.Nor can many animals either store or produce water in their bodies,as the camel and kangaroo rat can.So they must find ways to reduce water loss from their bodies to the lowest degree.
② Because very few desert animals can survive the high rays,the temperature,and the evaporation rate of a typical summer's day,most of the them are active during the night.Only after the sun has set does the desert come fully to life.The night is relatively cool,and the darkness provides protection,not only from the sun,but also from other animals and birds.So the coming of darkness is the signal for water and food.When morning comes,most of them seek shelter again.Many go under ground;nearly all find somewhere shady and they can avoid the sun rays there.
③For many kind of insects,living in the desert is easier than for animals.Like many desert plants,they have a waterproof skin which prevents water loss by evaporation.In addition,some insects spend all or most of life below ground.Here,for most of the year at least,there is some wetness,and it is generally cooler than on the surface.

22. Valuing Water 珍惜水资源
① Humanity uses a little less than half the water available worldwide.Yet occurrence of shortages and droughts are causing famine and distress in some supplies.Since the world's population is expected to double in the next 50 years,many experts think we are on the edge of a widespread water crisis.
② But that doesn't have to be the outcome.Water shortages do not have to trouble the world——if we start valuing water more than we have in the past.Just as we began to appreciate petroleum more after the 1970s oil crises,today we must start looking at water from a fresh economic perspective.We can no longer afford to consider water as a virtually free resource of which we can use as much as we like in any way we want.
③ Instead,for all uses except the domestic demand of the poor,governments should price water to reflect its actual value.This means charging a fee for the water itself as well as for the supply costs.Governments should also protect this resource by providing water in more economically and environmentally should ways.
④ No matter what steps governments take to provide water more efficiently,they must change their their institutional and legal approaches to water use.Rather than spread control among hundreds or even thousands of local,regional,and national agencies that watch various aspects of water use,countries should set up central authorities to coordinate water policy.

23. Man and His Natural Habitat 人类及其自然栖息地
① Ecology is that branch of science which concerns itself with the interrelationships between living things (plants and animals) and their natural environments.Human ecology specializes in man's relationship to his natural environment.
② Ecology has become greatly important in recent years because of man's devastating impact on his habitat.High schools and colleges across the nation offer special courses in this subject area to make young people aware of the impact of air,water,and land pollution on the quality of man's environment.To the growing population of our natural environment we must add soil erosion,destruction of forests,and deposits of large accumulations of solid wastes as causes for concern the future quality of our natural environment.
③ Rachel Carson,in her far-reaching book,Silent Spring,alerted many Americans to the dangers of land and water pollution to the natural wildlife.Man's excessive use of pesticides has destroyed much of the bird life and fish in out land.She predicted the wholesale extinction of the natural animal life.Many experts have confirmed Rachel Carson's fears that the basic problem of ecology is to determine how far man has changed his environment to such an extent thatit has now become a question as to how long life can be preserved on our planet.Whether the problem is real or imaginary,experts agree that man has become the victim of his creativeness and genius.Extensive research has shown that natural habitats are changing because of the spectacular advances in the application of science and industry.