Why do you think Sumerians thought that cleansing was necessary before entering shrines?

Because cleaning standards in Ancient Summer were not very high. Sanitation was not readily available for everyone. Besides, most people in Ancient Summer were farmers, working in the fields every day, where they would obviously get their clothes and body dirty.

Finally, a shrine is a place that every culture in the world deems sacred, and where people need to enter in a clean state of mind, and with clean clothes and body as well.

john maynard keynes developed new economic theories in response to the stock market crash of 1929. great depression of the 1930s. first and second world wars. economic boom of the 1950s.