This is truly a once in a lifetime opportunity.

He drew a hendecagon shape.

His party trick is perfect for livening up the party.

He continued to write that report all night.

My birthday is on the thirty-first.

He is known as a one-hit wonder singer.

Nitrogen monoxide is a cause of air pollution.

His shoes are a symmetrical pair, perfectly matching left and right.

Our project is scheduled to be completed on the eleventh day of the month.

He was walking around the room wearing only underpants.