Did you hear his voice?

I work in the marketing division.

The Great Eastern Japan Earthquake is one of the most damaging earthquakes in Japanese history.

My heart was healed by the beautiful scenery of Nara.

Learning Modern English is important for smooth international communication.

He wrote a sentence using a pronoun.

My grandfather was born in the 1900's.

Abstract algebra is a branch of mathematics that studies algebraic structures.

Abstract algebra is a field of mathematics that studies algebraic structures in an abstract way.

The Paleolithic is the first era of human history.