He is very interested in ecology.

Marine pollution is a global issue, and all countries should cooperate to find a solution.

He is an expert in ecology.

The process of terraforming is part of transforming other planets into a habitable environment for humans.

Earth science is an important field of study for unraveling the mysteries of nature.

I am an Earthling.

We are searching for extraterrestrial life.

I maintain my health by doing aerobic exercises every day.

There are only inanimate objects in this room.

The use of bioweapons is prohibited by international law.