The following five definitions relating to primary care should be taken together. They describe the care provided to the patient, the system of providing such care, the types of physicians whose role in the system is to provide primary care, and the role of other physicians, and non-physicians, in providing such care.
Where The U.S. Gets Its Oil. America is one of the world's largest oil producers, and close to 40 percent of U.S. oil needs are met at home. Most of the imports currently come from five countries: Canada, Saudi Arabia, Mexico, Venezuela and Nigeria.
We use the term 'petroleum products after crude oil is refined in a factory. Crude oil can exist either deep down in the earth's surface or deep below the ocean beds. In oil drilling, a structure called 'derrick' is built with pipes going down to the reservoir and bringing the oil to the surface. Saudi Arabia, USA, Russia, China and Iran are among the top crude oil producers in the world, and the USA is the world's biggest consumer of crude oil, followed by China.