How come some versions of eminems song "my name is" are different?

i kno there is a cnesored version. but sometimes in the uncensored it will say "my english teacher wanted to flunk me in junior high, thank a lot, next semester ill be 35" then other times it says "my english teacher wanted to have in junior high, the only problem was, my english teacher was a guy" and another difference was when he says "extraterristrial, runnin over pedestrian, in a spaceship, while they screamin at me lets just be friends!" and then other times its "extratersstrial, killin pedestrians, rapin , while they screamin at me lets just be friends!". they are both uncensored becuase words like f u c k are used but still these parts are changed in some verisions. how come?