晕...我的英语水平有限,点出点来你再重新组织吧...
1.沉没成本 sunk cost
Cherie should not go to the cafeteria,for the money spent on permit can't be changed whatever she does,it is a sunk cost.What's more,if she chose to go to the cafeteria,she would spend more money.A rational decision is just ignoring the permit.
2.替代品 substitute
Apples are substitute for bananas.So when there's a fall in the price of apples,the demand of bananas will decrease,for people will consume apples instead of bananas.(Reflected in the diagram is the left-shift of Demand Curve)Yet the suppliers of bananas don't know the change (so Supply Curve remains).They will have to reduce price to attract consumers,yet still can't sell all bananas(in the diagram the new equilibrium is below the initial one,both price and quantity decrease)
大概需要画个图,就是D曲线左移,均衡点变低.不知道够不够详细
3.我也不知道中文怎么讲,exploited opportunities==就是没有改进的余地,达到帕萨特最优
In a market where price is below equilibrium,the sellers' reservation price is lower that of buyers.So he can increase his price equal to that of buyers and gains more profit.Then the market reaches equilibrium and no one can benefit without someone loses,or to say no mutually benefitical exchanges.
不知道合不合你的意思...