微笑传染嘴角的甜蜜微笑传染嘴角的苦涩
[wēi xiào chuán răn zuĭ jiăo de tián mì wēi xiào chuán răn zuĭ jiăo de kŭ sè]
'A smile can be contagious, bringing sweetness or bitterness.' It describes the power of smiles to affect mood, whether positive or negative, influencing both the smiler and others around them.