Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Keon's book is very comprehensive.

The Truth About Breast Cancer is a thorough book about overall health in general and very in depth regarding Breast Cancer prevention. It will be a valuable assest in everybody's library - whether for yourself or as a gift. Keon details many facts and figures that will astonish most readers. The tone of this book is urgent yet not suffocating. The choice is yours to make - live a healthy life by following Keon's guidelines and his Revised American Diet. You will need to put this on an easily accessible shelf as you will be constantly using it for reference - the recipes in the back of the book are delicious!