大学英语四级模拟试题（九）3

passage　2
　　　just　30　years　ago　some　700　million　people　lived　in　cities.　today　the　number　stands　at　1,800　million,　and　by　the　end　of　the　century　it　will　to　3,000　million—more　than　half　the　world's　estimated　population.　by　the　year　2000　an　estimated　650　million　people　will　crowd　into　60　cities　of　five　million　or　more—three　quarters　of　them　in　the　developing　worl　d.only　a　single　first　world　city—metropolitan　tokyo,　which　will　have　24　million　people—is　expected　to　be　among　the　global　top　five;　london,　ranked　second　in　1950　with　ten　million　people,　will　not　even　make　2000's　top　25.in　places　where　rates　of　natural　population　increase　exceed　three　per　cent　annually—meaning　much　of　the　third　world—that　alone　is　enough　to　double　a　city's　population　within　20　years.　but　equally　powerful　are　the　streams　of　hopeful　migrants　from　the　countryside.

　　　what　faces　and　confuses　urban　planners　is　the　huge　scale　of　these　trends.　there　have　never　been　cities　of　30　million　people,　let　alone　ones　dependent　on　roads,　sewer　and　water　supplies　barely　adequate　for　urban　areas　a　tenth　that　size.　and　the　flood　of　new　arrivals　in　swelling　third　world　cities　far　overtakes　the　supply　of　jobs—particularly　as　modern　industries　put　a　premium　on　technology　rather　than　manpower.　so　it　will　be　virtually　impossible　to　find　permanent　employment　for　30　to　40　per　cent　of　the　1,000　million　new　city　inhabitants　expected　by　the　year　2000.

　　　despite　the　terrible　conditions　that　the　city　newcomers　face,　their　numbers　are　growing　at　rates　as　much　as　twice　that　of　the　cities　themselves—and　every　step　taken　to　improve　their　living　conditions　in　the　slums　only　attracts　more　migrants.