This book uses a unique historical perspective to explain the causes of menstruation, the changes in women's emotions before and after menstruation, and the history and evolution of menstrual products, so that girls can have a correct understanding of menstruation and let go of their anxieties and doubts. During the few days when their "good friend" comes, they can still study and play normally, and even if an emergency occurs, they can respond calmly.
本书以独特的历史视角科普了月经产生的原因，女性经期前后情绪的变化，月经用品的历史与演变，让女孩们对月经有正确的认识，放下不安与疑惑，在“好朋友”来的几天里，依然可以正常学习、玩耍，即使出现紧急情况，也能从容应对。
本书以独特的历史视角科普了月经产生的原因，女性经期前后情绪的变化，月经用品的历史与演变，让女孩们对月经有正确的认识，放下不安与疑惑，在“好朋友”来的几天里，依然可以正常学习、玩耍，即使出现紧急情况，也能从容应对。
