故事背景设定
□But kissing□is not□j□st a romantic g□□t□re—i□ also□has□scient□f□c b□□□fits. W□en□we kiss, □ur □□a□n□ release a□cocktail of ch□mica□s like oxytocin, dopami□e, and serotonin, known □□ the□"love□hormone□□"□These □he□icals □a□ □educe stress, boost mood, and □reate fe□lings of □ttachment and □onding. Kis□ing□also s□reng□hens o□r immune sys□em□b□ expos□ng us to a v□□iety of□bacteria that □an h□□p bu□ld □mmunity.