How much do you know about marijuana?

In November 2012, Massachusetts became the 18th state to legalize the use of marijuana for medical purposes. Voters in Washington and Colorado passed initiatives that would make their states the first in the country to allow recreational use of the drug. But under federal law, the sale of cannabis remains illegal. And the US Food and Drug Administration states that marijuana has "no currently accepted medical use in treatment in the United States." How much do you know about marijuana? Take our quiz and find out: