Once a student leaves the classroom after taking an exam, the student may not re-enter the classroom as long as that exam is still taking place. The student's leaving the exam will be taken to signify that the student has finished that exam. We won't know until we've taken the exams and carefully thought about the results. I have to do this because we will be covering a lot of material at the forefronts of knowledge. This isn't like high school, where everything has been taught for years to hundreds of other people, and so how to teach it has been thoroughly tested by the time it gets to you.
College is a lot like juggling.
The Dean will think it's weird, but I'll say you're a talented bunch, and if I need to, I'll personally argue on your behalf. I really hate awarding poor grades. Still, if for some reason you get into trouble serious enough to want to drop the course, such as getting so far behind you can't catch up, don't just stop coming to class and think that will be the end of it. Dropping a class is a serious matter. Try to avoid such a terrible waste of time and tuition money by keeping on top of things - for example, by always keeping up with your reading assignments.