[填空题]
Today’s lecture is about the mass {{U}} (1) {{/U}} of
the world’s population. There are two major {{U}} (2) {{/U}} why people
are moving to cities. The first reason is {{U}} (3) {{/U}}. People are
moving to the cities because that’s where they can find {{U}} (4) {{/U}}
and earn money. The second reason for the move to cities has to do with
{{U}} (5) {{/U}} of life issues: comfort and {{U}} (6) {{/U}}.
Cities often offer better {{U}} (7) {{/U}}. And then for many, city life
is just more {{U}} (8) {{/U}}. An interesting consequence of urbanization
is that the average {{U}} (9) {{/U}} of people in the countryside is
increasing, while that of the cities is {{U}} (10) {{/U}}.
Three key {{U}} (11) {{/U}} can be identified in our cities. First
of all, they’re getting bigger. Most cities are bigger now than ever before.
Cities are also changing shape. They’re getting {{U}} (12) {{/U}} ,
because land is getting more and more expensiv
