He decided to challenge the exploration of the Dark Continent.

My friend is working in mainland China.

The Asian Continent is the largest continent on Earth.

Antarctica is the coldest place on Earth.

In geology, the continental slope refers to the point where the seabed becomes steeply deep.

The Australian continent is the smallest continent on Earth.

A terrestrial planet may have an environment similar to Earth.

He believes in the geocentric theory.

He is an expert in geophysics.

Global warming is a big issue that affects all of us.