The doctor examined the affected area in detail.

He gave a detailed explanation about the plan.

He went to the library to investigate the incident.

My father is a doctor.

He was known as a quack doctor in that town.

Even though he is a doctor, he doesn't take care of his own health. It's truly a case of 'physician, heal thyself'.

In order to maintain health, it is important to adhere to the saying, 'Eat moderately to avoid the doctor.'