【正确答案】正确答案： Aging population refers to a phenomenon that the number of elderly people in a country or a region rises. Declining birthrates and rising average life expectancy are the two major factors contributing to aging population. According to the traditional standards of the United Nations, an aging society is one in which the population of people over 60 years old exceeds 10 percent of the total population. Influenced by the one-child policy, mainland China rapidly entered an aging society in 1999. At the end of 2011, the number of people over 60 years old accounted for more than 13.7 percent of the total population of that time. Aging population in China has brought about a series of social problems such as the relative shortage of labor force and the increase in expenses of national welfare and medical services. Therefore, it is urgent to solve the aging population problem in China

【答案解析】解析：1．“生育率下降和人均寿命延长是导致人口老龄化的两大因素”中的“下降”“延长”并不必翻译成动词。可译为declining birthrates and rising average life expectancy，用动名词短语表达汉语中的动词概念，更符合英文表达习惯。 2．“由于计划生育政策的影响”可以译作owing to the influence of the one-child policy或influenced by the one-child policy。后者由动词的过去分词短语作状语，相当于原因状语从句，更加简洁。 3．“劳动力资源相对短缺、国家福利和医疗服务支出增加”这一句翻译成the relative shortage of labor force and the increase in expenses of national welfare and medical services，用名词短语表达出汉语的动词概念，符合英文一个句子里用动词较少的结构特点。 4．“中国人口老龄化问题亟待解决”这句话翻译成it is urgent to solve the aging population problem in China，用it作形式主语，不定式to solve…作真正主语，避免头重脚轻。