新东方名师推荐:四六级优秀范文背诵(13)

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2010年6月四六级考试真题答案点评汇总

13 Skyscrapers and Environment

In the late 1960's, many people in North America turned their attention to environmental problems, and new steel-and-glass skyscrapers were widely criticized. Ecologists pointed out that a cluster of tall buildings in a city often overburdens public transportation and parking lot capacities.

Skyscrapers are also lavish consumers, and wasters, of electric power. In one recent year, the addition of 17 million square feet of skyscraper office space in New York City raised the peak daily demand for electricity by 120, 000 kilowatts-enough to supply the entire city of Albany, New York, for a day.

Glass-walled skyscrapers can be especially wasteful. The heat loss (or gain)through a wall of half-inch plate glass is more than ten times that through a typical masonry wall filled with insulation board. To lessen the strain on heating and air-conditioning equipment, builders of skyscrapers have begun to use double-glazed panels of glass, and reflective glasses coated with silver or gold mirror films that reduce glare as well as heat gain. However, mirror-walled skyscrapers raise the temperature of the surrounding air and affect neighboring buildings.

Skyscrapers put a severe strain on a city's sanitation facilities, too. If fully occupied, the two World Trade Center towers in New York City would alone generate 2.25 million gallons of raw sewage each year-as much as a city the size of Stanford, Connecticut , which has a population of more than 109, 000.

四级历年真题（2001-2009）

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2005年6月	2005年12月	2006年6月	2006年12月	2007年6月
2007年12月	2008年6月	2008年12月	2009年6月	2009年12月

六级历年真题（2001-2009）