This math problem includes multiple variables.

He is studying about the metamorphosis of insects.

This is an old Japanese textbook that explains the usage of '變格' in detail.

His attitude changed dramatically.

His attitude changed drastically.

He likes to take a walk in the park at dusk.

I am surprised at this situation like a cataclysm.

We should always remember the power of Kannon in difficult times.

He said, 'Misery of life starts at literacy,' and spoke about the hardships of learning.

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.