I will participate in an obstacle race this weekend.

In this situation, the proverb 'it is best to submit to circumstances' applies.

This inorganic compound plays an important role in chemical reactions.

The study of organic compounds is an important field in chemistry.

Basic oxides react with acids to produce salt and water.

This area is affected by radioactive fallout from past nuclear tests.

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.