Groundwater is
A) surface water subject to industrial pollution.
B) water beneath the Earth's surface.
C) runoff water from acid rain.
D) None of the answers is correct.
Question 2
A molecule of ________ produces more than 20 times the warming of a molecule of carbon dioxide and remains in the atmosphere for up to 15 years.
A) methane
B) phosphorus
C) radon
D) chlorofluorocarbon