This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.

His blood congealed with fear.

He goes fishing in the sea every day.

In linear algebra, the upper triangular matrix plays a very important role.

By regularly checking the key performance indicators, you can understand the performance of the company and devise improvement measures.

Understanding the concept of 'Ha-line conversion sounds' is important in learning Japanese.

I will go to school.

He said, 'The advantages of heaven and earth are nothing compared to the harmony among people,' emphasizing the importance of teamwork.

He was lying face-up, looking at the stars.

Listening to music is really enjoyable.