The classroom is silent, only the sound of the wall clock can be heard, the exam is in progress. The exam supervisor is walking around supervising the students who are doing the exam questions. Yo Han was trying desperately to focus on his exams. He had been holding it for two hours when suddenly his stomach hurt in the middle of the exam. Sweat began to drip from his temples, his hands were shaking and sweaty. The writing on the exam paper seemed to be popping out and swaying. "ah damn! this must be because of the milk I drank earlier..."