Understanding requires questioning. You cannot attain understanding simply by passive absorbtion or by copying, either from lectures or from the reading. Understanding requires that your mind be actively involved. Questioning what you read, looking for relationships, and solving problems are active involvement and are essential to effective studying. Questioning often leads to confusion, which is a sign you are probably on the right track.
Confusion is resolved by thinking.
Professors and T.A.'s are here to help if your thinking gets stuck or you do not understand. The investigations are designed as study aids. If you have not worked at an investigation, you probably have not done a very good job. Choose one of the investigations from one of the assigned sets for your essay. DO NOT write on all the investigations in one set.