My boyfriend gave me a gift.

Everyone was surprised by the news.

We are advancing the project using the waterfall model.

The waterfall model is one method of software development.

We use a numerical surface model to understand the topography of this area.

The hidden Markov model is a statistical method that is widely used in natural language processing and speech recognition.

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

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

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.