I recently was late to biology, and we needed some leaves for practic(9th grade btw), but class teacher didn't state how many leaves exactly we needed. When I came, I opened the door, said "Excuse me..." she interrupted me and shouted "GET OUT". I was sitting next 40 minutes outside and listened how she was shouting on class. As I was told later, our biology teacher got some problems with our class teacher, as class teacher didn't state how many leaves we needed, and biology teacher wanted full package. Biology teach didn't even tell us what we needed earlier, when we had a lesson with her.