<span>Radon gas is a Groundwater entering a house through a home water-supply</span>
Answer:
I belive the answer would be D.
Give Brainliest plz
<span>simple organic molecules can form spontaneously under conditions like those thought to prevail early in Earth's history</span>
Answer:
b is the correct answer i guess
The heart must beat faster during exersise because by increasing the heart rate the body is able to increase cardiac output and deliver the necessary blood flow to the mucles