@jiangshanghan 牙菌斑会一层叠一层 非常稳固地附着在牙齿上 牙刷都很难刷干净 水流再大力 时间太短了 根本造成不了伤害
QOTO: Question Others to Teach Ourselves An inclusive, Academic Freedom, instance All cultures welcome. Hate speech and harassment strictly forbidden.
