He is known as an expert in library science.

She works as a librarian.

I commute by subway every day.

I commute from this train station every morning.

He is actively participating in social movements.

Subways are very convenient as a means of urban transportation.

There is a custom of eating rice cakes facing the favorable direction at the New Year.

This color has a high degree of saturation.

This sponge is saturated with water.

Let's calculate the normal of this line and plane.