April is the season of spring.

My family consists of four people.

He is working round the clock.

A positive-semidefinite matrix is one of the important concepts in linear algebra.

Kunminjōon is a book for teaching the correct pronunciation of Hangul.

He made a model of a regular dodecahedron.

He made a model of a regular icosahedron.

The Commonwealth of Independent States is an intergovernmental organization formed by part of the former Soviet Union.

This area is seriously contaminated with radioactive isotopes.

In Christianity, God is considered as the Trinity of the Father, the Son, and the Holy Spirit.