懂你英语Level 6 unit 2 part 4 listening

Aging populationThe worlds population is growing at a rate of a little more than 1% per year.However, not all segments of the population are growing at the same rate.This graph shows that the rates of growth have 3 different groups, children, adults and elderly. As you can see, while the population of children is fairly constant, the elderly population is increasing at the fastest rate. This is due to very low birthrates in developed country and birthrate declines most developing countries.As a result of these trends, the worlds population is aging. Between 2015 and 2050, the percentage of worlds population over 60 is expected to nearly doubled. In 2015, there were 900 million people over 60, in 2050, the number should be around 2 billion. Aging populations are becoming a huge problem in many countries, especially developing counties. It used to be that many elderly people lived with the family and helped take care of the next generation. They had a place to stay and people that helped to take care of them when they needed an assistance. Now however, many elderly people or senior citizens are left on their own. This is partly the result of people having fewer children and also because of the massive urbanization.Young and middle-aged audits have left the rural area for economic opportunities only available in large urban centers. As a result, there is no one to care for the elderly who were left behind to live on their own. This is especially true in developing countries. With an aging population, health problem becomes a growing concern.Some of the leading conditions that accompany aging including vision problems, hearing loss, diabetes and dimension such as Alzheimer disease. These problems can lead to disability that make it difficult to live without assistance. With diseases such as Alzheimers, people lose their memory and are unable to recognize their own children. Worldwide, more than 46% of people aged 60 and over have disabilities. Giving meals and medical care, for example, becomes both expensive and difficu