1·Low average population densities 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 population densities 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·Crown of thorns starfish normally live in high population densities.
刺冠海星通常生活在聚居的环境中。
4·The push pin color scheme shows population densities based on the color spectrum.
push pin颜色方案基于色谱显示人口密度。
5·In large parts of America, where population densities are lower, it would be much costlier.
而在美国，由于人口密度更低，投递费用还会更高。
6·Countries with relatively high population densities move to more spacious environments. This increases their visibility.
人口密度相对较高的国家换到了比较辽阔的地方，这样增加了这些国家在世界地图上的可见度。
7·The group of about 1,000 islands also has one of the lowest population densities in the world, making services difficult and expensive to deliver.
所罗门群岛约有1000座岛屿，是世界上人口密度最低的国家之一，这使得提供服务的难度大、成本高。
8·Considering the specific physiological and ecological functions and the influence on population densities, the deposition of secretions associated with oviposition is an evolutionary adaptation.
产卵分泌物是昆虫进化过程中的一种适应，一般具有特定的生理和生态学功能，影响着种群数量的变化。
9·After several generations of population growth, people packed the landscape in densities so high that communal pueblos may have been a necessary outcome.
经过几代人的人口增长，人们以如此高的密度挤满了这个地区，以至于公共聚居地的出现可能是一个必要的结果。
10·The background limit values and maximum allowable background densities of population in small towns of the area were calculated.
并对该地区小城镇人口的背景极限值和最大允许背景密度进行了推算。