📚 Practice Questions — Chapter 2
第2章 练习题
概念题 (Concept Questions)
Question 1 — Trade-offs
What is a trade-off in economics?
在经济学中，什么是“权衡”？
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A trade-off means choosing more of one thing results in having less of another due to scarcity. 权衡是指由于稀缺性，多选择一方意味着另一方减少。📝 点击查看解析
Trade-offs reflect the core problem of scarcity. 权衡反映了稀缺这一核心问题。Question 2 — Opportunity Cost
Define opportunity cost.
解释什么是机会成本。
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Opportunity cost is the value of the next best alternative forgone when making a choice. 机会成本是指做出选择时放弃的下一个最佳替代方案的价值。Question 3 — PPF
What does the Production Possibilities Frontier (PPF) show?
生产可能性边界（PPF）说明了什么？
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The PPF shows the maximum combinations of two goods producible with given resources and technology. PPF显示在既定资源与技术条件下可生产的两种商品的最大组合。Question 4 — Comparative Advantage
What is comparative advantage?
什么是比较优势？
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It is the ability to produce at a lower opportunity cost than others. 比较优势是以低于他人的机会成本生产某种商品的能力。Question 5 — Market
What is a market in economics?
在经济学中，市场是什么？
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A market is an institution where buyers and sellers interact to exchange goods and services. 市场是买卖双方进行商品和服务交换的制度。应用题 (Application Questions)
Question 6 — Student Time Allocation
A student has 6 hours to prepare for two exams: economics and accounting. Every 1 hour on economics increases the score by 5 points, while every 1 hour on accounting increases the score by 3 points. If the student spends all 6 hours on economics, what is the opportunity cost?
一名学生有6小时准备两门考试：经济学和会计。每学习1小时经济学提高5分，会计提高3分。如果他把6小时都用在经济学上，机会成本是多少？
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The opportunity cost is 18 points in accounting (6 hours × 3 points). 机会成本是18分会计成绩（6小时 × 每小时3分）。Question 7 — Tesla’s PPF
Tesla can produce either 100 sedans or 50 SUVs per week. If it produces 30 SUVs, how many sedans can it produce? What is the opportunity cost of 1 SUV?
特斯拉每周可生产100辆轿车或50辆SUV。如果它生产30辆SUV，可以生产多少辆轿车？1辆SUV的机会成本是多少？
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SUV opportunity cost = 2 sedans. 30 SUVs → 40 sedans (100 - 30×2). 每辆SUV的机会成本=2辆轿车。 生产30辆SUV → 只能生产40辆轿车。Question 8 — Inside the PPF
Country A is operating at a point inside its PPF. What does this imply, and give one policy to improve efficiency.
国家A的生产点在PPF曲线内。这说明了什么？举出一项提高效率的政策。
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It implies inefficiency or unemployment. A job training program can move production toward the frontier. 这意味着低效率或失业。通过职业培训可帮助经济体移向PPF边界。Question 9 — Oil Discovery
If a country discovers new oil reserves, how will its PPF change?
如果一个国家发现新的石油储量，它的PPF会如何变化？
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The PPF will shift outward, allowing more production of both goods. PPF会向外移动，使两种商品的产量都可能增加。Question 10 — Comparative Advantage
Country X: 10 steel or 20 wheat.
Country Y: 8 steel or 8 wheat.
Who should specialize in what?
国家X：10吨钢或20吨小麦。
国家Y：8吨钢或8吨小麦。
谁应专注于什么？
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- X’s opportunity cost of 1 steel = 2 wheat. - Y’s opportunity cost of 1 steel = 1 wheat. → Y should produce steel, X should produce wheat. → Y专注钢铁，X专注小麦。Question 11 — Gains from Trade
Explain how two countries can consume outside their PPF through specialization and trade.
解释两个国家如何通过专业化与贸易消费到PPF之外。
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Specializing in goods where each has comparative advantage and trading increases total output and expands consumption possibilities. 专注于各自的比较优势产品并进行贸易，总产出增加，消费可能性扩大。Question 12 — Household Labor Market
In the labor market, households provide labor and firms provide wages. Who is the supplier and who is the demander?
在劳动市场中，家庭提供劳动，企业支付工资。谁是供给者？谁是需求者？
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Households are suppliers of labor; firms are demanders. 家庭是劳动的供给者；企业是劳动的需求者。Question 13 — Circular Flow with Reduced Spending
If households cut spending, what effect does it have on the circular flow model?
如果家庭减少消费，这对循环流动模型有何影响？
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Less spending reduces firms’ revenues, lowering production and possibly wages. 消费减少会导致企业收入下降，进而减少产出和工资。Question 14 — Entrepreneur’s Risk
Why might entrepreneurs still pursue innovation even with high risks?
即使风险很高，为什么企业家仍然选择创新？
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Because potential rewards (profit, market leadership) outweigh risks. 因为潜在回报（利润、市场领导地位）大于风险。Question 15 — Property Rights
What happens to investment if property rights are not protected?
如果产权不受保护，投资会怎样？
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Investment and innovation decline as people fear their gains may be taken away. 投资与创新会下降，因为人们担心收益被剥夺。Question 16 — Patents and Innovation
Why do governments grant patents?
为什么政府要授予专利？
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To give innovators exclusive rights, encouraging R&D and innovation. 为了给予创新者专有权，鼓励研发和创新。Question 17 — Exam Time Allocation
If a student spends 2 hours on economics (score +10) and 3 hours on accounting (score +9), what is the opportunity cost of shifting 1 more hour to economics?
如果学生花2小时学经济学（+10分），3小时学会计（+9分），再增加1小时经济学学习的机会成本是多少？
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The opportunity cost is the lost accounting score (3 points). 机会成本是失去的会计3分。Question 18 — Government Spending Trade-off
If a government spends more on military, what is the opportunity cost?
如果政府增加军事支出，机会成本是什么？
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The opportunity cost is reduced spending on other goods like education or healthcare. 机会成本是教育或医疗等其他领域的减少支出。Question 19 — Inefficiency on the PPF
What does a point inside the PPF indicate in real life?
现实中，PPF内的点代表什么？
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It represents unemployment or underused resources. 它代表失业或资源未充分利用。Question 20 — Unattainable Points on the PPF
What must happen for points outside the PPF to become attainable?
要让PPF外的点变得可实现，需要发生什么？