They are my best friends.

I want to travel to many countries.

He has a deep interest in the European cultural sphere.

Category theory is a branch of mathematics that studies structures and their relationships.

The geosphere refers to the solid part of the Earth.

I work in the capital city area.

I was born and raised in the National Capital Region.

He wants to work in an Anglosphere country.

Protecting the biosphere is important for the future of the Earth.

He is dedicated to the study of the atmosphere.