中国的独生子女政策将保持人口出生率低下，但是由于平均寿命继续提高，抚养比率将会上升，这将降低国家的发展潜力。

China's one-child policy will keep birth rates low, but as life expectancy continues to increase, so will the dependency ratio, reducing the country's potential for growth.

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在这一时间段内，随着平均寿命和生育率的提高，石油输出国的人口开始迅速增加。

Over the same period, the populations of OPEC countries started to mushroom, as both life expectancy and fertility rates rose.

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由于因心脏病和癌症造成的死亡率下降了，因此美国人目前的平均寿命达到了历史最高点——77.6岁。

Declines in death rates from most major causes - including heart disease and cancer - have pushed Americans' life expectancy to a record 77.6 years.

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