He is an expert in paleoecology, pouring his passion into studying past ecosystems.

I am learning the basic concepts of differential geometry.

He is an expert in pomology and has contributed to the improvement of many fruit varieties.

He is known as the kapellmeister of a famous orchestra.

He is majoring in geology.

I am majoring in information science.

He solved the problem in a scientific way.

This reaction occurs through a chemical process.

He is majoring in economics.

He is an expert in bacteriology.