Please help with as many as possible. Thanks in advance!

8) How do patents affect markets?

9) What constitutes a monopoly?

10) Are there any justifications for a monopoly?

11) How does competition affect monopoly power?

12) What is different about monopolistic competition and perfect competition? (How about some examples of each)

13) What is the demand for a monopolistically competitive firm's product and what determines its shape? (Does advertising help monopolistically competitive firms or perfectly competitive firms - why/how?)

14) Describe an oligopoly and indicate what some of the issues that arise with it in terms of benefits/costs to society. How does the interdependence work and what constitutes a cartel?

15) This area of economics covering perfect (pure) competition through monopoly is called market structures. What I would like you to do is to is pick two structures and compare/contrast them.