Look at the keywords in your assignment and brainstorm any words, ideas, or associations that come into your mind. Do this without being critical of what you write, just get all the ideas on paper.
This visual tool will help you identify keywords and organize your ideas.
Start narrowing your ideas by being more specific with which words you are using.
Focus on: Canada, Health Concern, Lung Problems, Smog...
Narrow the geographical area and make the words more specific.
Canada Alberta, Health Medical Concern, Smog Air Pollution, Lung Problems Respiratory Problems