My new fountain pen is easy to write with.

I lost my mechanical pencil, so I'm going to buy a new one.

My new pen tablet is very easy to use.

Propene plays an important role in organic chemistry.

I used pentyne in an organic chemistry experiment.

He was writing a letter with an old-fashioned quill pen.

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.