How would a person most likely become ill from overly acidic water

Consider the last statement in the prompt: "people take such environmental factors into account in their choices when deciding where to live." do all people have a choice as to where they live? what factor plays a key role in this decision and may therefore play a large role in determining quality of life?

Apopulation of black bears depends on salmon from a stream for food. if a drought causes the stream to run dry one year, how will this likely impact the black bear population?

If assuming tasting ptc as a simple gene trait, what other genotype would you select to put in this missing genotype box that could result in this phenotype