Question

Which gas is a source of natural groundwater pollution?

A. Oxygen
B. Radon
C. Hydrogen
D. Carbon

i think its a
Ms. Sue
Oxygen is a polluter? I don't think so!
Anonymous
Which gas is a source of natural groundwater pollution?

A. Hydrogen
B. Oxygen
C. Carbon
D. Radon


Anonymous
Which of the following is not a type of mass movement that results from the force of gravity?

A. Deflation
B. Creep
C. Mudflow
D. Landslide

Candi
the answer is D. Carbon
kristina
well its not D. for sure cuz I took the Penn Foster test and it was wrong.