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

He lost everything.

This chemical reaction is very dangerous.

She overreacted to his words.

Nuclear reactions are used for mass production of energy.

She is planning a date with her current boyfriend.

My boyfriend gave me a gift.

Everyone was surprised by the news.

His body build is like that of a sports player.

Hypervitaminosis occurs when the intake of vitamins is too high.