Parodontium
牙周膜
🗣️ 情景例句
Claim concerning transportation should be referred to the shiping company.
涉及运输问题，应当向船运公司提出索赔。
Deep rivers move in silence, shallow brooks are noisy.
深水静静流，浅溪潺潺流。
Experiments have proved that children can be instructed in swimming at a very early age.
实验证明，儿童在很小的时候就可以开始学习游泳。