[不定项选择题]共用题干 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_______(51)this week from U.N.Habitat,a United Nations agency.
A century ago,_______(52)than five percent of all people lived in cities._______(53)the middle of this century it could be seventy percent,or_______(54)six and a half billion people.
Already three-fourths of people in_______(55)countries live in cities.Now most urban population_______(56)is in the developing world.
Urbanization can lead to social and economic progress,but also put_______(57)on cities to provide housing and_______(58).The new report says almost two hundred thousand people move _______(59)cities and towns each day.It says worsening inequalities,_______(60)by social divisions and differences in_______(61),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_______(62) quickly into rural areas,sometimes_______(63)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_______(64)cities to smaller ones.He sees a_______(65)toward"de-urbanization"across the nation. _________(56)
A.extension
B.raise
C.addition
D.growth