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.

I am studying Modern English.

The Neolithic was an important period in human history.

They used Euclid's algorithm to find the greatest common divisor.

Please teach me how to find the greatest common divisor.

You should not be deceived by the deceptive advertising of this product.

The colossal squid is the largest squid living in the deep sea.

The colossal squid is one of the largest squids in the world.