单选题
Urbanization and Its Influence
Over half the world"s people now live in cities. The latest "Global Report on Human Settlements" says a significant change took place last year. The report
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this week from U.N. Habitat, a United Nations agency.
A century ago,
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than five percent of all people lived in cities.
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the middle of this century it could be seventy percent, or
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six and a half billion people.
Already three-fourths of people in
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countries live in cities. Now most urban population
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is in the developing world.
Urbanization can lead to social and economic progress, but also put
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on cities to provide housing and
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. The new report says almost two hundred thousand people move
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cities and towns each day. It says worsening inequalities,
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by social divisions and differences in
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, could result in violence and crime unless cities plan better.
Another issue is urban sprawl (无序扩展的城区). This is where cities
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quickly into rural areas, sometimes
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a much faster rate than urban population growth.
Sprawl is common in the United States. Americans move a lot. In a recent study, Art Hall at the University of Kansas found that people are moving away from the
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cities to smaller ones. He sees a
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toward "de-urbanization" across the nation.