1. 地球上的人口增长很快.
The population of the earth is increasing very fast.
2. 一个显著的原因是拥有私家车的人增长很快.
One obvious reason is that car ownership has increased rapidly.
3. 城市经济增长很快,但也没有达到33％的增长率.
The urban economy is growing rapidly, but not at a 33 percent pace.