Question

Who was the scientist who discovered that some bacteria cause diseases?.

Answer 1

Robert Koch or Louis Pasteur

(The reason being Robert had made the discovery of microorganisms and study them for years finding out they could cause harm to our bodies but later on Louis had further the research finding about more diseases and making cures for them, so you can say either or, but I would go with Robert since he found out about them first, but if you want who further the research go with Louis)