I learned how to calculate the harmonic mean in math class.

We need to calculate the harmonic mean of this dataset.

The Earth revolves around the sun in a fixed orbit.

He likes to take a walk in the park at dusk.

He is learning Ancient Greek language.

An irregular galaxy is a type of galaxy that does not have a definite shape.

The spread of the internet has made it easier to obtain information.

Learning irregular verbs is difficult.

He is a small man like a dwarf.

We are developing new technologies to mine bauxite.