His opinion is always rational.

I am surprised at the irrationality of this system.

This system is too irrational to understand.

This project requires a lot of work.

He believes that he is a psychic.

I learned how to calculate rational expressions in math class.

A kana ligature is one of the notation methods in Japanese.

I have been to Jiulong.

A new policy was implemented by the executive order.

The advance sale tickets for the concert are already sold out.