He divided the tree and made firewood.

He always proactively suggests new ideas.

He is my greatest enemy.

I think his idea is innovative.

Real analysis is a branch of mathematics that studies the properties of real numbers and the functions on them.

He is a very quiet person.

I like watching the stars on a quiet night.

The stillness of this park calms the mind.

I like watching stars in the still night.

In Buddhism, 'Sei' means the tranquility of the mind.