1. Answer whether the following statement is true or false, and explain why: "As Economics is a social science, then it is not possible to conduct closed-experiments (so we use models as a simplification of reality)" 2. Answer whether the following statement is true or false, and explain why: "Opportunity cost is always the value of time for not choosing certain alternative" 3. Answer whether the following statement is true or false, and explain why: "A market is when you have lots of firms supplying and lots of consumers demanding" 4. Answer whether the following statement is true or false, and explain why: "Comparative advantage is the ability of an individual, firm or country to produce cheaper than competitors" 5. Explain correctly the Law of Demand