Solving a linear equation is difficult.

Mr. April First is my best friend.

He was reading a book in his room all day.

The first storm of spring blew fiercely, and the cherry blossom petals fluttered up.

The strong sense of impatience I feel waiting for his return is painful.

The strong sense of impatience I feel waiting for his return is painful.

This is a once-in-a-lifetime opportunity.

He and his brother look so alike, they seem like the very same person.

Their teamwork was in complete harmony, and it was beautiful.

Carbon monoxide is a colorless, odorless gas, and it is dangerous to inhale.