I am surprised at the irrationality of this system.

This system is too irrational to understand.

This compound is an unsaturated hydrocarbon.

That information is unnecessary.

That information is completely unnecessary.

I learned how to solve inequalities in math class.

He was punished for his disobedience to the rules.

We should always remember the power of Kannon in difficult times.

Learning irregular verbs is difficult.

Unsaturated fatty acids are said to be good for health.