He is working day and night.

He is studying Japanese script.

It's very interesting to learn about the history of the medieval times.

Let's meet at the actual place.

A centralized political system is one in which all power is concentrated in the central government.

I can't forget the taste when I first ate borscht.

She used to be my wet nurse.

He gave me good advice.

He advised me to continue studying.

This stratum is thought to be millions of years old.