In organic chemistry, tartaric acid plays an important role.

His calculating nature sometimes causes problems.

He decided to become a member of the Communist Party.

My birthday is on the thirteenth.

He deeply studied the three branches of sutras in Buddhism.

This drink has a strong carbonic acid.

Nitric acid is a chemical substance with strong acidity.

I turned thirty years old.

He is good at writing prose.

The acidity of this lemon is very strong.