2018年中考题型集训(三)任务型阅读（含答案） When we say someone is in a blue mood. It means he or she is unhappy or sad. Are you feeling a little blue? Here are some fast and easy ways to cheer you up. Do exercise. When you exercise, your brain gives out a chemical called Endorphins(内啡肽). This chemical makes you feel happy. That is why exercise is good for you.