Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A great read!

This book is a must-read for any solar enthusiast. It just goes to prove that mankind is a fickle beast. When all of the fossil fuels get out of reach or become too expensive, we always fall back to the sun for the remedy. A proven track record for over 2500 documented years and I am certain even more before that, you can't help but admit that the sun is the one resource that keeps on giving and the price never varies - free for the taking. Ken.