Social insurance 社会保险
参考答案：
政府提供的强制性保险。预防道德危害或逆向选择等市场不灵问题，以增进社会福利。
That little boy became _____. Nobody liked him.[ ]
A. bad and worse
B. more and more bad
C. worse and worse
D. better and better
下月即将满60周岁，不知如何办理退休手续？还有办理退休手续后，养老金每月什么时候发？
