My pet is a dog.

This main road is convenient for commuting.

He is an expert in dynamics.

He is an expert in dynamics, helping to solve complex problems in physics.

Understanding the principle of electromagnetic induction is very important in learning physics.

My father drives a truck.

The fire truck went into action because of the fire.

This song is my favorite.

I bought stamps at the post office.

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.