He was fishing using a swivel.

Studying the life cycle of this insect is very interesting.

She slipped a beautiful ring onto her finger.

He is an expert in ring theory and has written many papers in the field.

This document contains environment-dependent characters.

We must strive to protect the environment of the Earth.

My grandmother decided to get a bridge.

We must strive to protect the natural environment.

We should recycle to prevent environmental pollution.

I deeply sympathized with his story.