Personal post - student teachers

Recently in one of my classes we have a student teacher teaching us a unit. Usually this is alright but I don't think student teachers should be aloud to teach a grade 11 or a grade 12 class. In grade 11 or 12 is when grades really matter and it's hard when a student teacher comes in mid semester and messes with everything. They have a different way to do things then your regular teacher which you are not used to so it kind of screws you up. It also sucks because any work they give you is done once their gone, so even if you finished it you can't hand it in because they're gone. I get student teachers have to learn how to become a teacher and different grades are taught in different ways so they have to get a feel for it. But sometimes it can really mess a student up.