It is the fast growth period that the number and the formation of the elder in China in the 21st century. The proportion of the elder in the total population will increase gradually.

21世纪，是我国老年人口数量及人口老龄化的快速增长时期，老年人口在社会总人口中的比重将逐渐增大。

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The second slow growth period of fruit inosculated with the rigidification period of stone, and the first and the second fast growth period of fruit were two pivotal periods for fruit to grow.

果实第二次缓慢生长期与果实硬核期相吻合，果实第一次迅速生长期和第二次迅速生长期是果实增长的两个关键时期。

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This change has occurred in a period of fast population growth among low-income families.

而且这一变化发生于低收入家庭人口迅速膨胀的时期。

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Instagram is one of a cohort of young start-ups that have built products around the iPhone and have registered fast growth in a short period of time.

WSJ: Facebook to Buy Instagram For $1 Billion

They are still poor by EU standards, so can look forward to a period of fast productivity growth.

ECONOMIST: The financial crisis has made the euro look more alluring