In mathematics, a perfect number refers to a number where the sum of its divisors, excluding the number itself, equals the number.

This fish is completely farmed, and no capture is done in the natural environment.

He is immersed in the study of panmagic squares.

He grew up in a region where Mandarin is not very common.

He and I held a meeting to settle the matter.

He and I finally came to terms.

He often tells interesting yarns.

He is always talking about his big talk.

He is studying the ancient Tang language.

She loves reading fairy tales.