I will humbly return this wallet.

I returned the book to the teacher.

He is studying the history of the Balkan region.

He has a deep interest in the history of China and Japan.

My Chinese-Japanese character dictionary is very useful for learning Japanese.

He threw himself into the world of pleasure.

He found great pleasure in listening to music.

The benzene ring is a very important concept in organic chemistry.

Inside the ear, there are semicircular canals to maintain balance.

He is good at translating classical literature into Classical Chinese.