Okay I know this isn't an answer but you should try and answer some of those on your own cause that is a lot of questions to ask someone to answer.
Sorry if this is offending I really don't mean It to offend you.
The Varangians were Swedish vikings
It was c because they was the first one I am 98℅ sure.
a period of excessive speculation. The collapse of the stock market revealed that the much-trumpeted economic prosperity of the 1920s had been built on weak foundations. By this period, production had already declined and unemployment had risen, leaving stocks in great excess of their real value. Government policies throughout the twenties, such as high tariffs, soft enforcement of anti-trust laws, the absence of checks on speculation in real estate and the stock market, contributed to the implosion of the Great Depression.