He is studying the theory of bundles.

He received the letter challenging him to a duel and began preparing for the duel.

Gender roles are an important element in defining individual behavior in society.

His role is to fulfill his responsibilities as a leader.

Visual arts are a powerful means of expressing human emotions and thoughts.

It is important to understand the importance of health.

The optic chiasm is the part where the optic nerves cross, adjusting the left and right fields of view.

Shieko is my best friend.

Shiame is my best friend.

Shion is my best friend.