附录：接吻的好处（随便看看）
1. 额外的唾液可以洗掉牙齿上的细菌，有助于分解口腔牙菌斑，预防龋齿。
2. 一个认真的法式吻可以锻炼面部所有的肌肉，让你看起来更年轻、更快乐。
3. 接吻甚至可能有助于减肥，在一个非常热情的吻中，每分钟能燃烧两卡路里。
4. 有专家认为接吻会增强免疫系统——和另一个人交换菌群，可以刺激产生新的抗体，从而增加自己的内部防御系统。
参考文献：
[1] Murphy S, Dalton C. Out of touch? Visual load induces inattentional numbness. Journal of Experimental Psychology: Human Perception and Performance. 2016 Mar 14;42(6):761-765. https://doi.org/10.1037/xhp0000218
[2] Busby, D., Veronica R Hanna-Walker and Chelom E. Leavitt. A kiss is not just a kiss: kissing frequency, sexual quality, attachment, and sexual and relationship satisfaction. Sexual and Relationship Therapy (2020): 1-17.
[3] Karim, A.K.M.R., Proulx, M.J., de Sousa, A.A. et al. The right way to kiss: directionality bias in head-turning during kissing. Sci Rep 7, 5398 (2017). https://doi.org/10.1038/s41598-017-04942-9
[4] http://www.bbc.com/earth/story/20150714-why-do-we-kiss
[5] https://www.webmd.com/sex-relationships/features/kissing-benefits