Photochemistry is a branch of chemistry that studies chemical reactions affected by light.

Photochemistry is a branch of science that studies how chemical reactions proceed under the influence of light.

He is an expert in optics and has a deep knowledge of laser technology.

He is known for his scholarliness.

A palatal consonant is produced when the middle part of the tongue contacts or approaches the hard palate.

He couldn't say anything about issues outside of his field of expertise.

There are many different specialty stores in this town.

He is a specialist fool, with no interest in anything outside his field.

She is planning a date with her current boyfriend.

He lost everything.