He was hiding the fact that he was an illegitimate child.

Mr. Hiruma is my best friend.

Well, let's get started!

The mesentery plays a role in supporting the intestines.

Interracial marriage promotes diversity and understanding.

Intermolecular forces are an important factor in determining the properties of a substance.

His work progress is slow.

He is doing special exercises to strengthen the interosseous muscles of his hand.

He often uses four-kanji idioms.

Understanding the four-step conjugation in Japanese is difficult.