4. What led to the creation of a three-season calendar in Egypt?

Answer & Explanation:

In 1904 Eduard Meyer stated that the Egyptian calendar was invented about 4231 B. C., and some of the principal Egyptologists of his generation adopted this theory with minor modifications. In recent years it has been realized that 4231 B. C. was far back in the prehistoric period, long before the invention of writing, and of necessity later dates have had to be advanced for the adoption of the calendar as we know it. Primitive man in Egypt regulated his life entirely by the cycle of the Nile's stages. Nature divided his year into three well-defined seasons-Flood, Spring, and Low Water or Harvest, with the Flood Season, following the hardship of the Low Nile, the obvious starting point for each annual cycle. The Egyptian early recognized the fact that usually twelve moons would complete a Nile year, but his lunar reckoning always remained secondary to his Nile reckoning, and he never adopted solar seasons.  

For several centuries the calendar was fixed to the star and thus was approximately correct, but the experience of generations was apparently proving that the perfect year should be 365 days long, and in 2773 B. C. a year of this length was adopted, by the simple expedient of neglecting to readjust the calendar by annual observations. Since no change was ever permitted thereafter, the Egyptian calendar was only correct once in every 1460 years.

explanation:

7 - to develop an asian ally

11- the red scare

14   the power of military -industrial complex

17 - the economy grew quickly

24 - the separation of church and state was not important