Supplement: The official definition of health/ten criteria for measuring health given by the World Health Organization (WHO): 1. Energetic, able to cope with daily life and work calmly; 2. Optimistic, positive, willing to undertake tasks and not picky; 3. Be good at rest and sleep well; 4. Strong adaptability and adaptability to various environmental changes; 5. Have certain resistance to common cold and infectious diseases; 6. Proper weight, uniform posture, and coordinated proportions of all parts of the body; 7. Bright eyes, sharp reaction and no inflammation in eyelids; 8. White teeth, no defect, no pain, normal gums and no tooth decay; 9. Smooth hair, no dandruff; 10. The skin is shiny, elastic, easy to walk and energetic. Health means not only the absence of disease or illness, but also the complete physical, mental and social well-being. In other words, a healthy person should have a strong physique and optimistic mental state, be able to maintain a harmonious relationship with the social and natural environment in which he lives, and have good psychological quality.