21世紀大學英語應用型：自主練習4（簡體書）

《21世紀大學英語：應用型自主練習（4）/普通高等教育“十一五”國家級規劃教材》包括紙質平面課本、多媒體光盤和網絡學習平臺。課本的內容以主題原則編寫，無論是讀寫教程還是與之相配套的視聽說教程，每一個單元都有一個主題，並以此為主線進行內容編排，使不同的教程之間及課文和練習之間形成一個以同一主題為中心的有機整體。

《普通高等教育"十一五"國家級規劃教材:21世紀大學英語應用型自主練習4》的所有紙質教材都將轉化為電子材料放在教學平臺上，供學生自主學習使用。不僅如此，平臺上還有大量的擴展閱讀和輔助學習資料，供學生拓展學習使用。在網絡上為學生提供大量豐富的英語學習資源。除英語測試試題外，還包括視頻欣賞、經典英語歌曲、影片片段等，供學生課外自主學習，真正做到英語學習的連續性。

Unit 1Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingUnit 2Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingUnit 3Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingUnit 4Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingUnit 5Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingUnit 6Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingUnit 7Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingUnit 8Part One Vocabulary and StructurePart Two TranslationPart Three Reading ComprehensionPart Four WritingKeys

The Humanitarian Impact of Urbanization
While megacities appear more frequently in headlines and on development agendas, overall growth in urban centers of 10 million or more inhabitants is expected to level out. Instead, over the next 10 years, cities of less than 500,000 will account for half of all urban growth.
Two sides of the urban coin
All this growth is not necessarily a bad thing. As David Satterthwaite of the International Institute for Environment and Development （IIED） points out, the speed at which a city grows—if it is responding to economic opportunities-is a benefit, not a problem. “A very large part of the economic value in any country is being generated in the urban areas,” Satterthwaite says. “Even in developing nations, where 60 to 70 percent of the population is in rural areas, you still have more than half the economy-and often more than that-generated in urban areas. ”
The problem is not growth, but unplanned growth. In 2001, 924 million people, or about 31 percent of the world's urban population, were living in informal settlements or slums, 90 percent of which were located in the developing world. By 2030, the number of worldwide slum dwellers is projected to reach two billion. In the Bangladeshi capital of Dhaka, 3.4 million of the city's 13 million residents live in 5,000 slum and squatter settlements.
What this translates to is abject poverty, disease, and appalling conditions. Take Dhaka: every time the river level rises, it floods the illegal clusters of tiny stilted huts built on the flood plain with smelly water full of factory effluence. In Delhi, the water problem is one of scarcity as slum dwellers fight each other to gain access to the working standpipe in their area and often go without for days at a time. Malnutrition is often highest in slums,as unemployment means people are too poor to purchase produce that could be grown on the land.
Defining a “slum” and the “urban poor” invariably focuses on what people lack-access to education, social services, employment, safe and affordable water, sanitation and housing, and residential status. In many cases, they live in sub-standard housing, in public spaces, or in squatter settlements near major urban areas.
“More threatening than the village”
Throughout the 20th century, city growth was largely fuelled by rural to urban migration. Today,however, cities are mostly growing from within-more people are born than are dying in urban centers.
But the fact that mortality rates are generally lower in cities masks a health crisis in slums.Worse, those most affected by this urban healthcare divide are children. A 2006 analysis in the International Journal for Equity in Health found that in 15 sub-Saharan African countries the difference in child malnutrition within cities was greater than the urban-rural divide.
As the UN's 2006/2007 State of the World's Cities report notes: in Ethiopia, child malnutrition in slums and rural areas is 47 percent and 49 percent respectively, compared with 27 percent in non-slum urban areas. “Living in an overcrowded and unsanitary slum,” the report concludes, “is more life-threatening than living in a poor rural village. ”
Access to water
As urban populations increase, the number of people without access to improved water sources is also rising, doubling from 108 million in 1990 to 215 million by 2010. In dense city environments-and in even more dense slum environments-communicable diseases can quickly become epidemics, making the consequence of unsafe water and poor sanitation much more severe than in rural areas. And more people are affected due to city concentrations.
In addition to the outwardly identifiable impacts of poor access to water, sanitation, and health services, a dearth of services also perpetuates poverty.