The author urges countries with aging populations______. A．to modify their spending and social policies B．to increase their fertility rates by a large margin C．to persuade productive members to work longer D．to raise retirement ages to keep economy growing
A. A．to B.to C.to D.to
【参考答案】
D 根据第九段中的“Asforagingcountries，thecrisishasclearlyshownth......