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.
In the United States, the president is the head of state and ultimately responsible for the things that happen while he is in office, but it is impossible for him to manage every area of government personally. To facilitate management, each department of government is represented by a cabinet member. Each department is then in a better position to advise the president on issues that have to do with specific areas of governance.