You know the proverb, Smile and the world smiles with you, cry and you cry alone.
要知道有句格言“微笑,世界与你同欢乐;哭泣,你只能独自悲伤”。
The change between hot and cold temperatures makes the blood move around the shoulder and the damaged parts begin to repair themselves.
冷热交替使肩膀周围的血液循环,受伤的部位开始自己修复。