Which will occur if humans continue to overload water systems with excess nutrients?

Eutrophication.

Explanation:

This is the natural process of excessive enrichment of water with nutrients by which large amount of living organic matter grows in the water.lakes slowly develop large concentration of aquatic life, which eventually decays. Human activities have speeded up this natural process of eutrophication by adding mineral and organic nutrient in larger quantities.

1. (1.2kw)x(15/60hours) = .3kwh --> a

2. (5kw)x(90/60hours)x(8cents/kwh) = $0.60 --> d

3. microwave --> 1200 watts = (1.2kw)x(6/60hours) = .12kwh

coffee-maker --> 900 watts = (.9kw)x(10/60hours) = .15kwh

therefore, it requires more energy for the coffee-maker to do the same amount of work.

so the answer is a.

for 8 am not sure maybe yes?

for 9 if it is asking if the male is more or less it would be less

hope i even just a little : )