The doctor examined my heart using a stethoscope.

He always proactively suggests new ideas.

I bought a season ticket for commuting every day.

My commuter pass expires next week.

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

He solved the problem in a scientific way.

This reaction occurs through a chemical process.

He is good at tactical thinking.

He exercises every day and leads a healthy life.

Fundamental knowledge of mathematics is necessary to solve advanced problems.