He is troubled by chronic headaches.

She was wearing a very sexy dress.

In math class, I learned about the concept of intersection.

There is a possibility that unknown lifeforms exist on this planet.

His grandfather fought in the Second World War.

We dream of a day when all people can enjoy world peace.

We all wish for world peace.

A special event was held to celebrate his 100th birthday anniversary.

He was organizing documents using a shakudan.

The volume ratio of this engine is 10:1.