He called me back immediately after he hung up the phone.

The potential energy of this ball is proportional to its height.

His usual location is the seat at the very back of the library.

The place of articulation is a very important concept in phonetics.

He is majoring in Sinology at university.

He can speak Chinese fluently.

He was born and raised in China proper.

My friend is working in mainland China.

We celebrate the New Year based on the Chinese calendar.

The Communist Party of China is the largest political party in China.