My high school courses in the United States were so much fun. In chemistry class, to understand how a double bond (双键) forms, we made models out of eggs and crayons. In math, to explain the Riemann theory, our math teacher put on a wig (假发) and played a rock song on his guitar. In English, to fully understand Macbeth, we went to the hall and acted it out without any preparation. In history, to help us memorize important dates and facts, we played mini basketball flashcard games. All these fun things made each class and each day enjoyable.