Coffee is not recommended. . Coffee, red bull and chocolate all have exciting effects. . But caffeine in coffee not only has a refreshing effect, but also has a diuretic effect. . Therefore, after drinking coffee, there may be symptoms of frequent urination, which is not conducive to the exam. . The effective substance in red bull is mainly taurine, which has the function of refreshing and anti-fatigue. . Suggestion: drink a cup of hot milk the night before the exam and go to bed early. . At noon on the day of the exam, I dozed for another half an hour, and the effect was very good. . If you are excited, you can bring red bull and chocolate. It seems that you have a long exam time, and chocolate can just replenish energy. Red bull? Drinking it half an hour before the exam will make you excited all afternoon. . I tried it before. . . Good luck in the exam. .