The means of mass communication such as television, radio, newspapers, and the internet, are collective known as the
a) communication service
b) news shows
c) public broadcast service
d) media

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products