Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Very sophisticated prose and symbolism

Unless your teen has good knowledge of what happened in Germany during World War II, an exceptional vocabulary and the ability to read flowery and vague symbolic passages (many) and make sense of them, it will be a tough read. The book is fine if you're reading it with them, but if they're reading it independently they will be quite frustrated and only get about 70% of what's going on. Knowledge of communism, Nazi philosophy, what happened in concentration camps (specifically), and why Germany would have been bombed by someone (the book never says who is bombing) are essential. The end of the book leaves too many unanswered questions - it's as if the author thought 550 pages was enough and didn't finish his story lines well at all.