Thermochemistry is a part of chemistry that deals with the reactions of heat and matter.

Chemical pollution has a serious impact on the health of the Earth.

This shirt is made of chemical fiber.

He is an excellent doctor.

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

He admitted that it is difficult to execute the plan, saying 'it is easier said than done.'

My spouse is a doctor.

Well then, I'm off.

We are developing new technologies to mine bauxite.

It is reported that North Korea has conducted another underground nuclear test.