机会成本（opportunity cost）：“机会成本（Opportunity Cost）”是每位学生接触经济课程所需要知道的一个基础术语。它表示了错失一个机会以承担完全不同机会的成本。当我们面临鱼和熊掌这种选择权衡时，如果你选择吃鱼，那么不能吃熊掌就是你这个选择的机会成本。
This is a data response, which requires students to think over the question given through four perspectives, namely, knowledge, application, analysis and evaluation(if necessary).
First and foremost, students should locate the key words in the question above-mentioned for the purpose of the starting point when they seek the pertinent answers.
Here, the core words are ‘opportunity cost’. So students can follow this to brainstorm some related knowledge points. For example, the definition of opportunity, the relationship between opportunity cost and PPF and so on, which can be the economic theories to justify the answers in terms of knowledge. Regarding the application, students can illustrate where and how the economic concepts are applied in reference to the evidence mentioned in the text. Then, with everything necessary provided, students can analyze the efficiency and effect of the theories principles in a specific situation. Sometimes, the question given can be kind of open-ended. For instance, what does the opportunity cost mean to governments or students? Will it be a blessing or not? If so, what are the potential results or what should be done to minimize the side effects. The sub-questions above are just some versions for reference. Students do not necessarily cover all. Maybe one or two pieces will do because evaluative part can show off their economic reasoning.
For governments, its opportunity cost when they finance students may be lower tax revenue, more funds that should have been available for other areas of spending like primary education or health or possible decrease in government borrowing.
For students, their contribution to tuition fee may come at the cost of not going into debt, spending the tuition fees on something else, getting a job and earning income instead of studying or increased leisure.
In addition, diagram is more than welcomes in data response. For this part, students can also borrow PPF curve to reveal the meaning of opportunity cost by a brand new lens.
Anyway, students are encourage to think divergently. There are many channels in the list to shed light on the economic knowledge point.