大学英语：Aging has become a social problem

　　1.老龄化已成为一个社会问题。
　　Aging has become a social problem.
　　2.人们反对这一看法来自于出生率的下降。
　　The resistance to the idea is caused by the falling of birthrates.
　　The fall of birthrate resulted in people's objection to the idea.
　　3.人们寿命的长短取决于种种因素。
　　The length of life depends on various factors.
　　Expectation of life is due to various factors.
　　4.估计寿命是预计一个人能活得平均年数。
　　Expectation of life is the average numbers of years that a person is expected to live.
　　The expectancy of life is the prediction of average years a person can live.
　　5.长寿在改变我们的生活，改变我们的社会。
　　Long life is altering our life as well as our society.
　　Long life is changing our lives, changing our society.