Question

Which is TRUE about burning fossil fuels?

A. clean fuels burn with a yellow frame

B. the fuel reacts with oxygen

C. most fuels contain a low percentage of carbon

D. little heat energy is released

Answer 1

B makes the most sence. thr other choices just dont make any logical sense at all. every time fuel is burned it does react with oxygen

Answer 2

For this, I would say B.
I know that is a fact. Oxygen is needed to keep fires going.
IDK for A.
C is false. Coal is almost pure carbon. 
D is also false as coal and other fuels give off massive amounts of heat when burned.