This is my ALL-TIME-FAVORITE Dr. Seuss book! It's definitely in my top-5-favorite of ALL TIE! This is a story about the Lorax, about tree, about nature, and about caring for the world around us. It teaches children many valuable lessons. I would put it at a Level M in the Fountas & Pinnell scale because it is pretty difficult language for young kids to read and comprehend by themselves.
As an activity, I would have students choose their favorite quotes from the book and decode the or explain them. I observed this being done when I was observing in a 5th grade classroom and the kids loved it! Then they got to watch the movie to enhance understanding and they loved it. I was in 9th grade the first time I saw the movie and I thought it was hilarious, so it's really great for all ages.