In the text the author emphasizes the importance of studying animal diseases to help humans. what are some other examples in which scientists have to study something harmful to better protect people from it

There is nothing inherently wrong with being gay. speaking generally, opposition to gays are usually judged on people's moral basis whether it be religion, experience or other factors. to conclude, there is no objective answer to this question only subjective ones that rely on people's idea of what is right and wrong.