<p>hey, do any of you guys know why princeton review decided, this year, to split its AP physics b and c review book into two books one specifically geared for "b" and one for "c"?? If you guys know, are there any major differences between the older combined edition and the newer split editions? Amazon still happens to sell both editions and I will need to purchase books for next year. Just wondering which one or two to get. Thanks guys.</p>