老人牙医学

例句：

1. 1.The dentist is performing an extraction on a patient.
   牙医正在给病人拔牙。
2. 2. She has been to the dentist for regular check-ups.
   她定期去牙医那里做检查。
3. 3.The dentist advised her to brush her teeth twice a day.
   牙医建议她每天刷牙两次。