His strong point is mathematics.

I'm hungry and I want to eat something.

Because of his hunger, he hurried his meal.

This page is still blank.

There are still blanks in this form.

The air conditioning in this room is very efficient.

This factory uses compressed air to operate the machines.

In mathematics, an empty set refers to a set that does not contain any elements.

This battleship has enhanced antiaircraft capabilities.

This area has a strong air defense system.