Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Good book, pitty it is so useless.

Everything said in the review is true. The answers are all there. Unfortunately answers are of little use without the questions. As explained in the review above, the questions can be downloaded from somewhere but where that somewhere is I do not know. The URL reference in the book is outdated, and the publisher (MacMillan) has stopped printing the book and hence all support. So if you like answers to unknown questions, go for it. Otherwise DON'T!