Look at the diagram in Unit 12a (in Task 1 on p. 90 in your coursebook). Study it carefully and answer at least two of the following questions. Don´t forget to give reasons for your opinions. In addition, respond to at least one contribution of one of your fellow students.
1) What does the diagram show? What is it for?
2) What problem does it solve? Where is it used?
3) Can it work? Could it be used in the Czech Republic?