新东方英语背诵美文50篇 第三十一篇 Botany
BotanyBotany, 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 th...
日期:2010-04-28新东方英语背诵美文50篇 第三十二篇 Plankton
PlanktonScattered through the seas of the world are billions of tons of small plants and animals called plankton. Most of these plants and animals are too small for the human eye to see. They drift ab...
日期:2010-04-28新东方英语背诵美文50篇 第三十三篇 Raising Oysters
Raising OystersIn the past oysters were raised in much the same way as dirt farmers raised tomatoes - by transplanting them.First, farmers selected the oyster bed, cleared the bottom of old shells and...
日期:2010-04-28新东方英语背诵美文50篇 第三十四篇 Oil Refining
Oil RefiningAn important new industry, oil refining, grew after the Civil war. Crude oil, or petroleum – a dark, thick ooze from the earth – had been known for hundreds of years, but littl...
日期:2010-04-28新东方英语背诵美文50篇 第三十五篇 Plate Tectonics and Sea-fl
Plate Tectonics and Sea-floor SpreadingThe theory of plate tectonics describes the motions of the lithosphere, the comparatively rigid outer layer of the Earth that includes all the crust and part of ...
日期:2010-04-28新东方英语背诵美文50篇 第三十六篇 Icebergs
IcebergsIcebergs are among nature’s most spectacular creations, and yet most people have never seen one. A vague air of mystery envelops them. They come into being ----- somewhere ----- in faraw...
日期:2010-04-28新东方英语背诵美文50篇 第三十七篇 Topaz
TopazTopaz is a hard, transparent mineral. It is a compound of aluminum, silica, and fluorine. Gem topaz is valuable. Jewelers call this variety of the stone “precious topaz”. The best-kno...
日期:2010-04-28新东方英语背诵美文50篇 第三十八篇 The Salinity of Ocean Wate
The Salinity of Ocean WatersIf the salinity of ocean waters is analyzed, it is found to vary only slightly from place to place. Nevertheless, some of these small changes are important. There are three...
日期:2010-04-28新东方英语背诵美文50篇 第四十篇 American black bears
American black bearsAmerican black bears appear in a variety of colors despite their name. In the eastern part of their range, most of these bears have shiny black fur, but in the west they grow brown...
日期:2010-04-28新东方英语背诵美文50篇 第三十九篇 Cohesion-tension Theory
Cohesion-tension TheoryAtmospheric pressure can support a column of water up to 10 meters high. But plants can move water much higher; the sequoia tree can pump water to its very top more than 100 met...
日期:2010-04-28新东方英语背诵美文50篇 第四十一篇 Coal-fired power plants
Coal-fired power plantsThe invention of the incandescent light bulb by Thomas A. Edison in 1879 created a demand for a cheap, readily available fuel with which to generate large amounts of electric po...
日期:2010-04-28新东方英语背诵美文50篇 第四十二篇 Statistics
StatisticsThere were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedicated to keeping orderly records of government units (states a...
日期:2010-04-28新东方英语背诵美文50篇 第四十三篇 Obtaining Fresh water from
Obtaining Fresh water from icebergsThe concept of obtaining fresh water from icebergs that are towed to populated areas and arid regions of the world was once treated as a joke more appropriate to car...
日期:2010-04-28新东方英语背诵美文50篇 第四十四篇 The source of Energy
The source of EnergyA summary of the physical and chemical nature of life must begin, not on the Earth, but in the Sun; in fact, at the Sun’s very center. It is here that is to be found the sour...
日期:2010-04-28新东方英语背诵美文50篇 第四十五篇 Folk Cultures
Folk CulturesA folk culture is a small isolated, cohesive, conservative, nearly self-sufficient group that is homogeneous in custom and race with a strong family or...
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