重点讲解：
1. hinge on 有赖于；取决于；
The fate of the world economy may hinge on the answer.
世界经济的命运，可能都有赖于这个问题的答案。
2. set out (清晰而有条理地)陈述，阐述，说明；
The government has set out its timetable for the peace talks.
政府已制订出和平谈判的时间表。
3. come down (成本、水平或数量)下降，降低；
Interest rates should come down.
利率应该降低。
4. at risk 处境危险；有风险的；
Hundreds of thousands of people are at risk.
有几十万人正处于危险中。