We have maintained a good relationship for a long time.

His research is deeply related to my project.

My cat is very cute.

A stray cat is playing in my garden.

It is important to understand the importance of health.

His explanation was impossible to understand.

They are my best friends.

His success had a cause-and-effect relationship with his efforts.

He and I are related by blood.

There is a complex love triangle between them.