Two of the folders contain exercises. The others contain examples from Dave Fisher's CSS Lectures
Instructions for the Exercises are here. As before you can ignore the github checkout instructions.
There are solutions for all of the exercises.
Exercises part 1: Do 0 and 1 from "primary_selectors_and_combinators_exercises"
Exercises part 2: Do 2 from "primary_selectors_and_combinators_exercises" and 0 from advanced_selector_exercises.html
As usual, ask for help as needed.