A force is a push or a pull. When one object pushes or pulls another object, you say that the first object is exerting a force on the second object.
The Marcellus Shale also categorized as the Marcellus formation is a marine sedimentary rock unit of middle Devonian age found in eastern North America. It elongates throughout the major of the Appalachian Basin.
The shale comprises huge unexploited reserves of natural gas, which makes it an attractive target for export and energy development. There are comparatively scarce presences of fossilized marine fauna found in the Marcellus, however, these fossils are still essential to paleontology.
For example, the Marcellus comprises the primogenital known varied assemblage of thin-shelled mollusks, still possessing well-preserved shell microcomposition. It is also where goniatite, an extinct shelled swimmer identical to a squid, make their initial presence in the fossil record.
Because bacteria mutates that's why we have a new flu vaccine every year , because strains of DNA in the bacteria change all the time.
