【正文】 mize ice included wrapping up the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the delicate balance of insulation and circulation needed for an efficient icebox.But as early as 1803, and ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting stuff in the tubs of his petitors to pay a premium price for his butter, still fresh and hard in neat, onepound bricks. One advantage of his icebox, Moore explained, was that farmers would no longer have to travel to market at night in order to keep their produce cool.31 British ColumbiaBritish Columbia is the third largest Canadian provinces, both in area and population. It is nearly times as large as Texas, and extends 800 miles(1,280km) north from the United States border. It includes Canada’s entire west coast and the islands just off the coast. Most of British Columbia is mountainous, with long rugged ranges running north and south. Even the coastal islands are the remains of a mountain range that existed thousands of years ago. During the last Ice Age, this range was scoured by glaciers until most of it was beneath the sea. Its peaks now show as islands scattered along the coast.The southwestern coastal region has a humid mild marine climate. Sea winds that blow inland from the west are warmed by a current of warm water that flows through the Pacific Ocean. As a result, winter temperatures average above freezing and summers are mild. These warm western winds also carry moisture from the ocean.Inland from the coast, the winds from the Pacific meet the mountain barriers of the coastal ranges and the Rocky Mountains. As they rise to cross the mountains, the winds are cooled, and their moisture begins to fall as rain. On some of the western slopes almost 200 inches (500cm) of rain fall each year.More than half of British Columbia is heavily forested. On mountain slopes that receive plentiful rainfall, huge Douglas firs rise in towering columns. These forest giants often grow to be as much as 300 feet(90m) tall, with diameters up to 10 feet(3m). More lumber is produced from these trees than from any other kind of tree in North America. Hemlock, red cedar, and balsam fir are among the other trees found in British Columbia.32 Botany Botany, the study of plants, occupies a peculiar position in the history of human knowledge. For many thousands of years it was the one field of awareness about which humans had anything more than the vaguest of insights. It is impossible to know today just what our Stone Age ancestors knew about plants, but form what we can observe of preindustrial societies that still exist a detailed learning of plants and their properties must be extremely ancient. This is logical. Plants are the basis of the food pyramid for all living things even for other plants. They have always been enormously important to the welfare of people not only for food, but also for clothing, weapons, tools, dyes, medicines, shelter, and a great many other purposes. Tribes living today in the jungles of the Amazon recognize literally hundreds of plants and know many properties of each. To them, botany, as such, has no name and is probably not even recognized as a special branch of “ knowledge” at all.Unfortunately, the more industrialized we bee the farther away we move from direct contact with plants, and the less distinct our knowledge of botany grows. Yet everyone es unconsciously on an amazing amount of botanical knowledge, and few people will fail to recognize a rose, an apple, or an orchid. When our Neolithic ancestors, living in the Middle East about 10,000 years ago, discovered that certain grasses could be harvested and their seeds planted for richer yields the next season the first great step in a new association of plants and humans was taken. Grains were discovered and from them flowed the marvel of agriculture: cultivated crops. From then on, humans would increasingly take their living from the controlled production of a few plants, rather than getting a little here and a little there from many varieties that grew wild and the accumulated knowledge of tens of thousands of years of experience and intimacy with plants in the wild would begin to fade away.33 Plankton浮游生物. / 39。s, the United States experienced a declining birth rate every thousand women aged fifteen to fortyfour gave birth to about 118 live children in 1920, in 1930, in 1936, and 80 in 1940. With the growing prosperity brought on by the Second World War and the economic boom that followed it young people married and established households earlier and began to raise larger families than had their predecessors during the Depression. Birth rates rose to 102 per thousand in 1946, in 1950, and 118 in 1955. Although economics was probably the most important determinant, it is not the only explanation for the baby boom. The increased value placed on the idea of the family also helps to explain this rise in birth rates. The baby boomers began streaming into the first grade by the mid 194039。s on the schools. In the 192039。26. International Business and Crosscultural CommunicationThe increase in international business and in foreign investment has created a need for executives with knowledge of foreign languages and skills in crosscultural munication. Americans, however, have not been well trained in either area and, consequently, have not enjoyed the same level of success in negotiation in an international arena as have their foreign counterparts.Negotiating is the process of municating back and forth for the purpose of reaching an agreement. It involves persuasio