You could be suffering from a serious illness that needs a doctor's care.

2017年12月六级真题（第二套）听力 Section C

You should never use any over-the-counter drug on a regular, continued basis, or in large quantities, except on your doctor's advice.

2017年12月六级真题（第二套）听力 Section C

This brief visit with mother nature cost me two days off from work, recovering from a bad case of sunburn and the doctor's bill for my son's food poisoning.

2017年高考英语全国卷1 阅读理解 七选五 原文

"Once on the calendar I protect this time like I would a doctor's appointment or important meeting", he writes.

2018年考研真题（英语二）阅读理解 Section Ⅱ

Once on the calendar I protect this time like I would a doctor's appointment or important meeting, he writes.

2018年考研真题（英语二）阅读理解 Section Ⅱ