Whenever he fails, he always sulks.

You need to use your head to solve this problem.

He is using that coat from winter to spring.

This invention brought about an epoch-making advancement in science and technology.

Please use the emergency stairs in case of a fire.

Due to the earthquake, the city declared a state of emergency.

He thinks that war is a necessary evil.

Do you understand the necessity of this project?

That information is unnecessary.

That information is completely unnecessary.