how well the flu vaccine is matched to flu viruses that are causing illness. Over a period of 31 seasons between 1976 and 2007, estimates of flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people.
metamorphic rocks form from heat and pressure changing the original or parent rock into a completely new rock the parent rock can be either sedimentary igneous or even another metamorphic rock the word metamorphic comes from greek and means to change form the diagram above shows you how the rocks on earth have been changed continually over time from one rock type to another
Metamorphic rocks are formed when heat and pressure below Earth's surface change a rock. Metamorphic rocks can be either foliated or nonfoliated. Foliated rocks are metamorphic rocks that have their grains arranged in parallel layers or bands. Slate is an example of a foliated rock.rganic rocks form when the remains of plant or animals are deposited in thick layers and become cemented together. Coal and limestone are both examples of organic rocks. Chemical rocks are formed when minerals that are dissolved in solution crystallize. Rock salt is an example of a chemical rock.