HW Questions help

Basically I am able to get 2 points on the following 3 questions and I got 1 on each. Our teacher has given us the chance to redo them and was hoping anyone could answer these to the best of their ability and see what I can add on.

2. Does intellectual property encourage or discourage innovation?
3. Explain why pollution is an example of market failure. Explain how we
can use market policies (i.e. prices) to solve it. Include an example.
4. Describe two problems that arise in markets with asymmetric information.
Include an example for each one.