This document contains 4 questions asking the reader to: 1) Draw a causal loop diagram showing vicious cycles that lead to escalating violence between football fans. 2) Develop a stock-and-flow diagram and time series graphs to model a student's knowledge based on studying, forgetting, and initial knowledge. 3) Identify basic generic behavior patterns in a stock graph and describe the stock-and-flow structures that could produce each pattern. 4) Sketch the development of a stock variable over time when the net rate of change is shown in a figure, with the initial stock value being zero.