caffeine/ˈkæf.iːn/名词咖啡因,咖啡碱After pulling an all-nighter studying for exams, Mary relied on the powerful kick of caffeine in her morning coffee to jumpstart her day.在为考试翻夜的学习之后,玛丽依赖她早晨咖啡中强大的咖啡因来开启一天。想跟读,去练习