gingiva

例句：

1. 1. The dentist advised her to brush her teeth twice a day.
   牙医建议她每天刷牙两次。
2. 2. The patient's gingiva was severely inflamed.
   患者的牙龈严重发炎。
3. 3. Gingivitis is a common condition that can lead to tooth loss.
   牙龈炎是一种常见的状况，可能导致牙齿丢失。