楼主:
iLemonade (節能減碳愛地çƒ)
2016-12-03 01:30:00Some mucous membranes (such as the rectum) have a single layer of cells while others (such as the foreskin, urethra, mouth and vagina) have multiple layers. The more layers, the more protection there is.应该是说 肛门性行为就是高风险群 不管男女啦 没有歧视意思 只是想认真讨论...