Low average populationdensities are characteristics of most underdeveloped countries.
平均人口密度低是大多数不发达国家的特点。
2
The cultivation of crops has expanded into progressively drier regions as populationdensities have grown.
随着人口密度的增长,农作物的种植已经扩展到了越来越干旱的地区。
3
After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome.