The study of cosmic rays may hold the key to unraveling the mysteries of the universe.

He proposed a new theory about cosmology.

He is interested in the design of spacecraft.

He is excited about living in outer space.

This accessory is sold separately.

This accessory is sold separately.

This word has several variant forms.

I live in Hobetsu.

I am planning to go to Monbetsu, Hokkaido next week.

It has been three months since parting ways.