I am planning to go to Inner Mongolia, an autonomous region of China, next week.

I have been to Outer Mongolia.

I have been to Chicago.

The International Phonetic Alphabet is an essential tool for linguistic research.

The treble clef is often used in musical scores.

He is good at reading the treble clef.

The Mesolithic is the era between the Paleolithic and the Neolithic.

The Bronze Age was an important period in human history.

The Azuchi-Momoyama period was a very important time in Japanese history.

The Azuchi-Momoyama period, also known as the Oda-Nobunaga period, was a very important time in Japanese history.