<p>My sister is 6 years younger than me. I usually buy current editions of all AP/SAT review books. Will she be able to use them in 4-6 years or should I just sell them?</p>
<p>My sister is 6 years younger than me. I usually buy current editions of all AP/SAT review books. Will she be able to use them in 4-6 years or should I just sell them?</p>