He is heating up the coffee.

He is an expert in chemistry.

He painted the sun into the landscape.

The heat is intense today, it's hard to go outside.

His passion for music is incredible.

His body showed a rejection reaction to the transplanted organ.

His single word triggered a chain reaction, and everything changed.

She overreacted to his words.

Nuclear reactions are used for mass production of energy.

I was surprised by his overreaction.