This is part of my collection, especially the Arabian cowry is rare.

He is conducting research on natural phenomena.

He is writing a thesis on phenomenology.

The simulacra phenomenon of imagining a face from three dots is one of the characteristics of the human brain.

He believes in psychic phenomena.

He is a perfectionist, and his approach to work is very strict.

This programming language is said to be Turing complete.

His performance was perfect and without blemish.

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

He is immersed in the study of panmagic squares.