How big is the area of the Indian Subcontinent compared to the size of the US?
A.
It is about the same size as the US.
B.
It is about 1/2 the size of the US.
C.
It is much larger than the US.
D.
It is about 1/4 the size of the US.

Which process is a source of outdoor air pollution? check all that apply. burning gasoline at a refinery releasing fumes at a chemical plant emitting particles from a dump truck releasing radon gas from a generator emitting carbon monoxide from a heater