Understanding your blood oxygen levels when you are at rest is something that you need to do if you want to make the most of the oxygen that's entering your body. Normal blood oxygen levels for the average American is about 90 to 100 percent oxygen saturation.
Chief of State. Every nation has a chief of state, a person who serves as the symbolic leader of the country and represents the nation. In the United States, the president both leads the government and acts as the chief of state, although this is not the case in many countries.
From Commander-in-Chief to the Guardian of the Economy, here are the President's many roles. The President of the United States has a very demanding job. The Constitution outlines many of the duties of a president, but modern society and technology have also changed and expanded the expectations placed on a president in some ways.