He earned a doctorate in the field of applied science.

My father is an expert in urology.

We are planning to go to the science museum this weekend.

He is an expert in planetary science.

Humanities is an academic field that studies human culture and society.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.

He is an excellent doctor.

He is a famous author, and his works are loved by many readers.

My spouse is a doctor.

That theory is unscientific and has no evidence at all.