Memo to all students:Sorry, kids, but for unavoidable personal reasons I was distracted when marking your papers, so I only really checked 50 out of the 100 questions. Some of you did pretty well though (I guess.) At least one of you got 45 of those 50 right, so if we made allowances for my failure to pay attention, that would probably be, like, 90% -- 4.5 stars out of 5. (Well done, Hannu!)But,