I heard a groan from his room.

I could hear a groan of pain coming from his room.

In festivals at shrines, sacred 'Gohei' are used.

He swore never to make the same mistake again from that bad experience.

He is fed up with that job.

He said he has seen a ghost.

Gouki is my best friend.

This chemical reaction occurs by the synthesis of two elements.

He is conducting an experiment to synthesize a new compound.

He is good at mixing medicines.