Here's yet another example of entertaining education on YouTube. Kids no longer have an excuse not to know stuff.
I particularly liked the answer to "Will this be on the test?" in the first minute. (Short version: Yes, all of this will be on the test, and you'll constantly be tested on it for the rest of your life.)
Of course, I'd have liked it even better if he didn't misuse "comprise" as if it were a synonym for "compose"... (NB: The parts compose the whole; the whole comprises its parts.)