Which of the following contributes to nonpoint source pollution in water?
a.
automobiles
b.
oil refineries
c.
paper mills
d.
water treatment plants

a.  automobiles

Explanation:

A non-point source pollutant is the one whose origin is unknown and cannot trace back to it's origination point. As the pollutant cannot be trace back it cannot be prevented from release and contaminating the environment.

The automobiles is the correct option because land or water vehicles may discharge oil or other emission products which cannot be trace back to the point of origination of the pollutant.

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.

it cools slower in the earth meaning the crystals have more time to form than lava on the surface