The reason is the spatial concentration of population and resources had the effect of increasing returns to scale.

原因是人口和资源的空间集聚产生了规模收益递增的效应。

youdao

With rapid growth of urban economy and concentration of population, there is urgent need to construct urban tunnel and underground projects.

随着城市快速经济的增长及人口的高度集中，城市隧道及地下工程的修建日益迫切。

youdao

It also offered that the concentration of population from natural villages to central villages should be regarded as one of the urbanization forms.

这种人口由自然村向中心村镇的集中也应看作是城市化的一种形式。

youdao

He said it was important for the restrictions to take into account the concentration of population near a store.

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"Rising fuel prices and the increasing concentration of the population in urban areas is bringing about serious logistical problems for the delivery of food, " he says.

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Yet he fails to mention Omar Mukhtar, the Libyan hero whose insurrection against the Italian invaders lasted 20 years, and the brutal suppression of which entailed herding much of Libya's population into concentration camps, where many died.

ECONOMIST: The history of the Arabic-speaking peoples