参考答案:
The BAst century is the era of aging population. China has entered the aging society since AIII, and becomes one of the developing countries with aging society at an early time. China is a country with largest elderly population in the world. The aging population is not only China’s own problems, but also affects the aging process of global population, thus attracting worldwide attention. As of the end of B0AA, the scale of China’s elderly population above the age of F0 is up to AHE million, with an estimated number of more than DC million to be added by the end of the "Twelfth Five-Year Plan" period, namely amounting up to BBA million in total. The aging population is surely to cause some new contradictions and pressures, and bring new challenges on economic and social development.
原子核对电子的吸引力称为结合力。
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