People worldwide are living longer． Today， most people can expect to live into their sixties and beyond． By 2050， the world's population aged 60 and older is expected to total 2 billion， up from 900 million in 2015． While this shift in proportion （比例） of a country's population towards older ages---known as ageing---started in high-income countries， for example in Japan， 30% of the population are already over 60 years old， it is now low- and middle-income countries that are experiencing the greatest change． （1） ____ At the biological level， ageing results from molecular （分子的） and cellular damage over time． This leads to a growing risk of disease and eventually death．（2） ____ That's why we say there is no "typical" older person． While some 70-year-olds enjoy extremely good health， other 70 year-olds are weak and require a lot of help from others． （3） ____ Retirement， relocation and the death of friends and partners are some of the possible reasons． For example， moving older people to a better house， which seems an admirable behavior， may do harm to their health eventually． （4） ____ Some people believe older people can be active and productive． A longer life brings opportunities， both for older people themselves and for society． They can pursue new activities such as further education or a new career． They also contribute in many ways to communities． （5） ____ This can lead to discrimination against older people． Therefore， society as a whole needs to address the ageist attitude by developing sound policies and offering various opportunities so that older people can experience fulfilling ageing．A． Nobody can ever escape from the ageing process．B． But these changes are only loosely linked to a person's age．C． Yet the extent of their contribution depends heavily on their health．D． Beyond biological changes， ageing is also related to other life changes．E． Although ageing is a universal trend， views towards older people divide．F． However， to others， older people are weak， dependent， and a burden to society．G． By 2050， many countries like Chile and China will have a similar rate of older people to Japan．

People worldwide are living longer． Today， most people can expect to live into their sixties and beyond． By 2050， the world's population aged 60 and older is expected to total 2 billion， up from 900 million in 2015．
    While this shift in proportion （比例） of a country's population towards older ages---known as ageing---started in high-income countries， for example in Japan， 30% of the population are already over 60 years old， it is now low- and middle-income countries that are experiencing the greatest change． （1） ____
    At the biological level， ageing results from molecular （分子的） and cellular damage over time．
    This leads to a growing risk of disease and eventually death．（2） ____ That's why we say there is no "typical" older person． While some 70-year-olds enjoy extremely good health， other 70 year-olds are weak and require a lot of help from others．
    （3） ____  Retirement， relocation and the death of friends and partners are some of the possible reasons． For example， moving older people to a better house， which seems an admirable behavior， may do harm to their health eventually．
    （4） ____  Some people believe older people can be active and productive． A longer life brings opportunities，  both for older people themselves and for society．  They can pursue new activities such as further education or a new career．  They also contribute in many ways to communities． （5） ____  This can lead to discrimination against older people． Therefore， society as a whole needs to address the ageist attitude by developing sound policies and offering various opportunities so that older people can experience fulfilling ageing．
A． Nobody can ever escape from the ageing process．
B． But these changes are only loosely linked to a person's age．
C． Yet the extent of their contribution depends heavily on their health．
D． Beyond biological changes， ageing is also related to other life changes．
E． Although ageing is a universal trend， views towards older people divide．
F． However， to others， older people are weak， dependent， and a burden to society．
G． By 2050， many countries like Chile and China will have a similar rate of older people to Japan．