Summary

It is time to sum up what we have learnt. Let's do it using a tool we know well: the digital presentation (PowerPoint).

You can do your presentation as you like, but let's follow a common guideline. The pwpt will include at least the following slides:

1. What do we mean with economical activities?
2. The law of supply and demand.
3. Oligopolies.
4. The cost of living in Spain.
5. The cost of living in Colombia.
6. Why is life more expensive in Colombia? I. Low salaries.
7. Why is life more expensive in Colombia? II. Expensive food.
8. What is a customs duty?

This is the basis. Your pwpt must be very clear.  You should cut and past anywhere. You should think and write.