My tooth hurts.

Fluorine is one of the chemical elements, and its symbol is F.

Health is very important.

His opinion is very important.

He is very healthy because he exercises every day.

Health is more important than anything else.

Hydrogen is the most abundant element in the universe.

My tooth hurts.

My tooth hurts.

By looking at the age of the teeth, you can tell the lifespan of an elephant.