He is viewing that situation as a serious problem.

He views that situation as a problem.

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.

A new approach is needed to solve this set of problems.

He is immersed in the study of panmagic squares.

The main problem with this project is the lack of communication.

This question text is too difficult, it's hard to understand.

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

He is an excellent doctor.