Tanaka is my best friend.

Nakagawa is my best friend.

We exist as a part of the material world.

The police found material evidence that he committed the crime.

This material evidence indicates that he is the culprit.

He is an expert in paleoanthropology, conducting research on the origins of mankind.

He is an expert in primatology and is engaged in the study of gorilla behavior.

The content of this book is very high quality.

He pawned his watch to get money.

He is quite a good cook.