I was surprised at his quick progress.

I am surprised at the quickness of this project's progress.

The population is increasing rapidly.

The population of Japan is decreasing.

Mr. Machi is my best friend.

I work in Shibuya Machi, Tokyo.

The population of this town is rapidly increasing.

There is a beautiful park in my town.

Demography is a branch of social science that studies the structure, distribution, and changes in human population.

Tokyo is the city with the highest population density in Japan.