What is the major obstacle in developing good human relations skills?
a. human relations aren't rewarding.
b. common interests won't to keep a conversation going.
c. people fear taking risks.

d i think its   answer d

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.