Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

Let me give you an example: I've read this book with much expectation, it was very boring all through out the book
The answer to this example can be: Negative
Here is why: Review writer does not like the book because it was boring, therefore it is a negative review.

OK. solve this:
i have read all of Wilbur's books and found that one learns a lot about Africa (with a few exceptions). you learn african history, economics, social problems, environmental problems, natural history, etc. in this one, you learn about the diamond industry and the history of the Namibian diamond coasts, while Wilbur weaves it into his "unputdownable" story. kind of like the Master of the Game with substance. for an even better look at Namibian history, try the Burning Shore.
Answer:
Positive