One of the most obvious changes in seasons occurs in the fall when the leaves of deciduous trees turn color and fall off. Evergreen trees remain green and lush. Have your carschoolers collect one specific kind of leaf and do some research on that tree. They can make sketches or photograph the tree at each season and report what they have learned in a journal. When it’s safe to do so, stop along the road and collect some leaves from both types of trees and compare them.