It permits a population to spread as the population increases, and it enables the colonization of new sites . 它使得种群在其增长的时候得以扩展它的分布区域并移居到新的场所。
After small number of pioneer emigrants made a successful start, they sent for their relatives and friends . 小批移民先驱移居海外获得成功后，他们就会把自己的亲戚朋友一起召来。
The mass immigration into the united states was particularly large and has attracted a great deal of scholarly attention . 成批移居美国的规模尤为庞大，这就引起了学者的很大关注。
Such colonists would be liable to modification, the principle of inheritance still betraying their original birthplace . 这类移居者虽易起变化，然而遗传原理还是泄露了它们的原产地。
Everything around him was full of her presence , continually reopening the wound . so he decided to emigrate . 他周围的一切都充斥着她过去的存在，不时地刺痛伤口。因此，他决定移居国外。
Probably nothing handed down by these early settlers has entered more deeply into the national way of life . 大约这些早期移居过来的人流传下来的影响，再没有比这一件更深入国民的生活方式了。
To the west of thirteen states stretched limitless lands into which settlers were now pushing in ever-increasing numbers . 十三州以西伸延着广阔无垠的土地，人数不断增加的移居民这时正向这些地方涌去。
The likelihood of a net fiscal drain from emigration is raised by the life-cycle patterns of public goods and migration . 公益设施和移民的生命周期模式，使得由出境移居而造成财政净流出的可能性增大了。
Heinemann, 77, like johnson a michigander displaced to california, has been a chief engineer at douglas since 1936 . 象约翰逊一样，七十七岁的海涅曼也是个离乡背井移居加州的密歇根人。从1936年以来他一直是道格拉斯公司的总工程师。
The high quality of japanese education outside the cities has meant that migrants have been able to cope with city life and compete for city jobs . 日本的非城市人口都有很高的教育程度，这就意味着移居者是能够适应城市生活并能够胜任城市的工作岗位。
