根据短文内容，从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
Are Societies Ageing Too Fast?
An ageing society is one in which the population of people over the age of 60 is increasing．The global population at present is about 6 billion with 1 person in every 10 aged 60 or above．_．This will mean that for the first time in human history the population of older persons will be larger than the population of children! What are the causes of this population change?
_．And another is that birthrates have dropped as people, especially women, are educated．Measures to slow population growth like China’s one-child policy, have also contributed to lowered birthrates．The increase in the aged population is not just an interesting trend, however; it also has severe implications for the future of global economies．
People traditionally retire at 65 and live on government pensions．_．Another concern is that as medical expenses increase with age, the demands of the growing aged population will eventually cause medical systems to face bankruptcy（破产）．
___．They suggest that because people are living longer, they ought to work longer, while governments need to establish a sound social security system．They also suggest that individuals start saving as soon as possible to ensure a financially secure retirement．People should also develop good health habits in their youth to ensure an active and productive old age．__．By finding cures for diseases like Alzheimer’s and cancer, medical bills and the need for care would be drastically reduced．
Finally, an important step to ensure a bright future for all is to do away with negative stereotypes that see valuable members of society only as pensioners or patients．It’s high time we stopped seeing ageing as a disease and started playing our parts in securing the future of our ageing societies．

A．Due to ageing problem, cities are facing more challenges．

B．Experts insist that steps should be taken now to prepare for the future．

C．As people grow older, a huge financial burden will be placed on the government．

D．Biomedical research is another tool we can use to deal with the problems of ageing societies．

E. One reason is that dramatic health advances have added 20 years to the average life-expectancy．
F. The United Nations projects that by 2050, it will be 1 in every 5．
G. As is known to all, good habits lead to good health．