Demography is a part of social science that studies the structure, evolution, and problems of human population.

I bought a new book.

He is good at fighting using the Tekkō-kagi.

I prefer the latter over the former.

They are engaged in a fight with the local gang.

That high-rise building has become a landmark of this city.

The binturong is a nocturnal animal that mainly lives in trees.

A unary operator operates on one operand.

Due to the skin effect, the current mainly flows on the surface of this wire.

You can use a spectrometer to examine the composition of a substance.