They are natural resources that are in limited supply or that take a long time to create
Radiography techs are trained to operate medical equipment that uses X-rays and other types of radiation. Ultrasound techs, referred to professionally as diagnostic medical sonographers, operate equipment that uses high-frequency sound waves to create images.
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Answer:
true they do I yes they do
Fossils can not be formed in igneous rock because before it cooled from the liquid magma state, any renants of fossils would be destroyed and melted... they form in sedimentary because thats where they can be buried and perserved the easiest, metamorphic would destroy them from the pressures and temperatures involved in there formations