Nitriding is often used to increase the surface hardness of metals.

In ancient Chinese astronomy, they used the earthly branches to express time and direction.

Mr. Ochi is my best friend.

Mr. Adachi is my best friend.

Mr. Chida is my best friend.

My father likes to tell dad jokes.

Mr. 𦿸父 was my high school teacher.

The wind rustlingly shook the leaves.

Kiyoshi is my best friend.

The Qing era was a very important period in Chinese history.