This is truly a once in a lifetime opportunity.

He drew a hendecagon shape.

We go on a family trip once a year.

His party trick is perfect for livening up the party.

He continued to write that report all night.

I'm praying for your recovery as early as possible.

My birthday is on the thirty-first.

My father is forty-one years old.

He is known as a one-hit wonder singer.

Nitrogen monoxide is a cause of air pollution.