He needed to fully control his vocal register to sing that song.

This book explains in detail how to use the 'Kyūjitai form of 声門' in old Japanese.

A big support was sent from his friends for his match.

We sent our full support to his match.

His lascivious voice echoed throughout the room.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.

He monitored the enemy's movements using a periscope.

By regularly checking the key performance indicators, you can understand the performance of the company and devise improvement measures.