The answer is b. His work became the basis for algebra.
Assuming you're referring to Frederick Lucas, he says that the preamble to the Declaration of Independence "sets the tone" for the rest of the document by making it clear why exactly the founders have submitted it.
About 5,000 Slaves served in the continental army, and by 1778 many states slaves who served in the American Revolution were granted their freedom.
Roosevelt's personality and political philosophy fitted the imperatives far more than they did the fashions of the times, so that the degree to which his behavior in the White House both hastened and shaped the dramatic growth of presidential power over the next seventy-five years must be seriously considered. Temperamentally, Roosevelt craved attention. Once in the White House, especially in view of the changed national and international circumstances, he could not fail to focus national attention on the presidency.
