Question

Many experts believe that if we continue to use fossil fuels at the rate we are now, we will run out of this natural resource by the middle to end of the twenty-first century. Fossils fuels, the remains of once living plants and animals, primarily recycle the element __________ and when burned, these fuels add the element back into our atmosphere.
A) carbon
B) oxygen
C) hydrogen
D) carbon dioxide

Answer 1

(Not sure if I posted this question in the correct area..)

Answer 2

what do you think? Any ideas?

Answer 3

I thought the answer was A.

Answer 4

yes i believe thats the answer