61. The problem of polllution has turned up on every continent on earth-even Antarctica. Winter Quarters Bay, on Antarctica, is the site of an important scientific station. Though the population here is never more than a few thousand people, this bay is as polluted as many city harbors. The reason is that for a long time, people at the station dumped garbage into the water. However, that has stopped now because of an international agreement. According to the agreement, scientific communities in Antarctica must
62. Four out of five people suffer from back pain at some time in their working lives. In the United States, it is the most expensive health problem in the workplace. In all, it costs people up to $60 billion in medical expenses and lost working time. Back pain is bad for business as well-it is the cause of 40 percent of all lost work days. That means a total of about 93 million sick days a year in the United States. Doctors now believe that exercise is the best treatment for many kinds of back pain. For this reason, some companies
63. Lichen are one of the few kinds of life that can survive in the mountains of Antarctica. These tiny plants live in small holes in the rocks. Outside, the extreme cold and strong winds prevent any life at all from surviving. Inside the holes, these lichen manage to find enough water and warmth to keep alive, even though they are frozen much of the time. This fact means that the lichen function extremely slowly and live a very long time. Scientists believe that a lichen may remain alive for thousands of years. If this is true, the lichen may
64. The Celts were never an empire or a nation, just groups of tribes. They came out of central Europe in about 1000 B.C? By 300 B.C., they had spread over all of Europe, from Turkey to Spain to the British Isles. Later they were conquered by the Romans and by various Garmanic tribes, but many Celtic legends stayed alive and are still familiar to us today. The best known of these is the story of king Arthur and the Round Table. There is some evidence that Arthur may really have been a Celtic leader in the early sixth century. Even if he never lived, his story almost certainly has Celtic origins, since it includes
69. Why do we grow old ? This is a question that people have asked since the beginning of history. Now biologists are looking for scientific answers to this question. They think that aging is part of our genetic program. From the evolutionary point of view this makes sense. A person who can no longer have children is not useful to the species, so he so She
70.Almost every language has some topic areas that are especially rich in vocabulary and idiomatic expressions .For example, the Inuit people who live in the far north of Alaska and Canada have many different ways to describe snow. The Irish, on the other hand, have a wide variety of describe a green landscape. Other examples can be found in Language relating to food. For instance, the French and Italian languages are rich in vocabulary for talking about wine, while American English has many ways to indicate how a steak should be cooked. We can conclude from all this that the development of a language is