He is majoring in chemistry at university.

He is an expert in chemistry.

This lemon is sour.

Please add a little vinegar to this salad.

Her eyes were a beautiful amber color.

Affine transformation is an important concept in geometry.

The Fourier transform plays a very important role in signal processing.

For some reason, I can't convert this sentence.

His body showed a rejection reaction to the transplanted organ.

His single word triggered a chain reaction, and everything changed.