13 Skyscrapers and Environment
In the late 1960s, 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 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 citys 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.
仙溪镇第一小学 人教PEP版英语三上《Unit 3 Let’s paint》PPT课件
人教PEP版英语三上《Unit 5 Let’s eat》 talk flash课件
人教PEP版英语三上《Unit 2 Look at me》PPT课件之五
人教PEP版英语三上《Recycle1》 Read and say flash课件
人教PEP版英语三上《Unit 2 Look at me》flash课件之二
人教PEP版英语三上《Recycle1》 sing flash课件之二
PEP Book 8 Recycle 1教材分析和处理
人教PEP版英语三上《Unit 5 Let’s eat》FLASH课件
人教PEP版英语三上《Unit 2 Look at me》 Let us talk B flash课件
人教PEP版英语三上《Unit 2 Look at me》PPT课件之二
人教PEP版英语三上《Recycle1》 Chant and color flash课件
人教PEP版英语三上《Unit 3 Let’s paint》lesson 15 flash课件
人教PEP版英语三上《Unit 2 Look at me》PPT课件之三
人教PEP版英语三上《Unit 2 Look at me》 Presentation flash课件
人教PEP版英语三上《Unit 6 Happy Birthday!》 Talk flash课件
人教PEP版英语三上《Unit 2 Look at me》 do flash课件之二
人教PEP版英语三上《Unit 3 Let’s paint》 check B flash课件
人教PEP版英语三上《Unit 3 Let’s paint》 What Colour is it PPT课件
人教PEP版英语三上《Unit 2 Look at me》flash课件之三
人教PEP版英语三上《Unit 6 Happy Birthday!》 Do flash课件
人教PEP版英语三上《Unit 1 Hello》 sing flash课件之一
人教PEP版英语三上《Unit 2 Look at me》 Story and Culture
人教PEP版英语三上《Unit 2 Look at me》 Morning exercise flash课件
人教PEP版英语三上《Unit 6 Happy Birthday!》 Learn flash课件
人教PEP版英语三上《Unit 6 Happy Birthday!》 Story time flash课件
人教PEP版英语三上《Unit 4 we love animals》 Sing FLASH课件
人教PEP版英语三上《Unit 1 Hello》Listen and match flash课件
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人教PEP版英语三上《Unit 2 Look at me》PPT课件之六
人教PEP版英语三上《Recycle1》 Color and say flash课件
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