Due to the earthquake, the city declared a state of emergency.

He is not that sort of person.

This is the kind of book I like.

He is not that kind of person.

Discrete mathematics is an important field that forms the basis of computer science.

He is majoring in applied mathematics at university.

He is passionate about researching pure mathematics.

He is a world-famous mathematician.

Combinatorics is a branch of mathematics that studies combinations of things.

Combinatorics is a branch of mathematics dealing with issues of order and choice.