This book is essentially a teaching machine. The way a teaching machine works is: it asks you a question. If you give the right answer, it goes on to the next question. If you give the wrong answer, it tells you why the ...This book is essentially a teaching machine. The way a teaching machine works is: it asks you a question. If you give the right answer, it goes on to the next question. If you give the wrong answer, it tells you why the answer is wrong and tells you to go back and try again.