The UN Food agencies are appealing to the richer countries to increase their foreign development aid and to invest in agriculture and economic safety nets in poorer countries.

VOA: standard.2009.10.14

I regard these books as safety nets.

课本只不过是救命稻草

耶鲁公开课 - 博弈论课程节选

I regard these books as safety nets.

课本只不过是救命稻草

耶鲁公开课 - 博弈论课程节选