Fossil fuels take _________ to form. Coal formation begins in __________, while oil and natural gas formation begins in _________. All fossil fuels require heat and ________ in order to form.

A. Centuries
B. Oceans
C. Millions of years
D. Swamps
E. Fossils
F. Pressure

1 answer

C. Millions of years
D. Swamps
F. Pressure