文章列表

• 1.新东方背诵文选 L41.American black bears
• American black bears appear in a variety of colors despite their name. In the eastern part of their range, most of these brown, red, or even yellow co...
• 2.新东方背诵文选 L42.Coal-fired power plants
• The 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 l...
• 3.新东方背诵文选 L43.Statistics
• There were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedicated to keeping order...
• 4.新东方背诵文选 L44.Obtaining Fresh water from icebergs
• The 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 app...
• 5.新东方背诵文选 L45.The source of Energy
• A 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...
• 6.新东方背诵文选 L46.Vision by
• Human vision like that of other primates has evolved in an arboreal environment. In the dense complex world of a tropical forest, it is more important...
• 7.新东方背诵文选 L47 Folk Cultures
• A folk culture is a small isolated, cohesive, conservative, nearly self-sufficient group that is homogeneous in custom and race with a strong family o...
• 8.新东方背诵文选 L48 Bacteria
• Bacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in microns. One micron...
• 9.新东方背诵文选 L49 Sleep
• Sleet is part of a person's daily activity cycle. There are several different stages of sleep, and they too occur in cycles. If you are an average sle...
• 10.新东方背诵文选 L50. Cells and Temperature
• Cells cannot remain alive outside certain limits of temperature and much narrower limits mark the boundaries of effective functioning. Enzyme systems ...