But it is simply a necessity for teachers: when a teacher has batches of exercise books from different classes, they should have different colors so it can be noticed when they mix up. Same applys to different subjects.
yeah, poor little doggie. I read in an article that the lady who trained and finally selected Laika also did not like it: picking a suitable dog knowing its the animals death. science is hard when dealing with non-humans (aka animals).
he just likes the wrestling theme ;)