He is traveling around the world as an ecologist.

We must strive to protect the natural environment.

We should recycle to prevent environmental pollution.

We need to solve the problem in the production environment.

It took a long time to set up the development environment.

A drop of water fell from the cup.

He knows the knack of cooking.

He gathered the wood chips and started a fire.

He set off on a journey to the north.

He cut his hair yesterday.