Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Fascinating Documentary on Mysterious Place

The content of this program if fascinating. The color is dynamite. Most worthy!Movile Cave is hidden deep underground in Romania, and has only recently been discovered. This cave was virtually totally isolated for 25,000 years. During that period, a unique ecosystem formed there, based on CHEMOSYNTHESIS (instead of our surface world's Photosynthesis) as the bottom of the food chain.The documentary shows how this newly-discovered ecosystem may have fundamental applications in space biology and the study of evolution.The documentary does best what documentaries SHOULD do: it entertains, and it teaches.