He practices every day to improve his sailing skills.

We plan to sail on a yacht during the summer vacation.

Studying the history of the Imperial Examination is important for understanding the past of our country.

Sexual intercourse is one of the basic human desires.

They were having sex in secret.

His resounding voice echoed throughout the room.

The ringing sound of the bell filled the quiet night sky.

Pronouncing the palatal sounds in Japanese is difficult.

His disease has spread to his vital organs.

We decided to start the game on the defensive.