Our teeth are hard, like built-in knives and forks in our mouths. However, they still feel pain quite easily. Why are teeth so sensitive (敏感的) to pain?
中报二十一世纪(北京)传媒科技有限公司版权所有,未经书面授权,禁止转载或建立镜像。 主办单位:中国日报社 Copyright by 21st Century English Education Media All Rights Reserved 版权所有 复制必究 网站信息网络传播视听节目许可证0108263 京ICP备2024066071号-1京公网安备 11010502033664号