The vice-chairman helped with the preparation of the meeting.

He missed school due to poor physical health.

He goes to the gym every day to train his longissimus muscle.

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.

I am very interested in natural science.

Natural numbers start from 0 and continue as 1, 2, 3, 4, 5, 6, 7, 8, 9.

Natural selection plays an important role in the evolution of organisms.

I was moved by the beauty of nature.

Calculating the natural logarithm is an important part of mathematics.

Natural language processing is the technology that allows computers to understand and generate human language.