Ignore how these concepts apply to your "business model" and focus strictly on the relationships describe in the various supply/demand concepts.
At this level of evaluating comprehension of comparatively simple concepts, I'm sure you would be able to find diagrams that illustrate these concepts visually (which tends to be easier to "absorb").
Or choose a product that is an "extreme" example. Something like insulin, or plain white t-shirts have obvious Supply demand relationships with respect to price.
Opps, I guess I should have finished reading this thread before replying....