His greed for money led to his downfall.

He observed the bird's feathers using a speculum.

You passed the exam, well done!

I like to soak in the bathtub after a long day.

He is always thought to be a greedy person.

He has a special ability.

This reaction occurs through a chemical process.

He is an excellent chemist who made many discoveries.

He is an expert in petrochemistry.

Understanding chemical equations is difficult.