I don't know if it's true for America, but you can't be jailed if you have small amounts of drugs - you can claim, and get away with saying, that the drugs are for medical purposes.
And Cannabis is legal in Holland I think, not England. It's only a Class C Drug.
Year 9 is the 9th year of school (10th actually, you start with Reception, then on to Yr. 1, then Yr. 2 etc.). The SATs are the first major exams...after the Yr. 6 SATs.
They test in English, Maths and Science. Not too important, but some Universities look at your results whilst thinking of whether to admit you.
Ahh.. you silly Brits. You and your crazy schooling system. Look at you there, all flaunting it. You know you like it. Aww... come on.. come on... you're silly....... haha.