Final answer:
Peter was throwing up in science class.
Step-by-step explanation:
Peter was throwing up in science class. It is unclear from the question what exactly Peter was doing in science class when he threw up, but it is likely that he was involved in a science experiment or activity that caused him to become nauseous. Nausea and vomiting can be caused by various factors, such as motion sickness or exposure to unpleasant smells or substances.