Blood Types. Distinct molecules called agglutinogens (a type of antigen) are attached to the surface of red blood cells. There are two different types of agglutinogens, type A and type B.
Fossil fuels are hydrocarbons, primarily coal, fuel oil or natural gas, formed from the remains of dead plants and animals. In common dialogue, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived from animal or plant sources.
There are three basic categories of fossil fuels: coal, petroleum  (or crude oil), and natural gas     More on Fossil Fuels    Fossil fuel is a hydrocarbon deposit occurring within the Earth's  crust, such as petroleum, coal, or natural gas, which when burned  with oxygen produce energy.