Instruct: Classify a given review into positive or negative sentiment.
Query: Excellent book.

I'm an environmental engineer in Missouri and I deal mostly with water pollution and wastewater treatment systems. I wanted to read this book so I could know more about actual stream ecology. My last class in stream ecology was many years ago and I felt I needed to know more. This book, which I'm still reading, is excellent and explains the topic in just enough detail for me. While I'm a bit buried in Latin names of the various organisms, it is still very useful information. Water pollution in the engineering sense is treated in much too a simplistic manner. And until the people in the state agencies and consulting firms have a more sophisticated understanding of water quality and how streams function, I think we will continue to waste a lot of money in wrong places and on the wrong solutions.