The Sumerians were the first people to migrate to Mesopotamia, they created a great civilization. Beginning around 5,500 years ago, the Sumerians built cities along the rivers in Lower Mesopotamia, specialized, cooperated, and made many advances in technology. The wheel, plow, and writing (a system which we call cuneiform) are examples of their achievements.
1 In a Parliamentary System, the head of state is usually a different person than the head of government (not in every country). 2  The HOG is often vested with more official power, but holds that position for a relatively short time.
A presidential parliamentary democracy is a democracy in which the chief executive (usually termed the Prime minister or the Premier is selected from among the members of the â¦ Parliament (the legislature). presidential legislative democracy is a system of government that  has a legislative branch that makes laws. The presidential or  executive branch carries out the policies â¦ and laws. Answered. In Political Theory.