what did churchill mean when he describe russia as being "a riddle wrapped in a mystery inside an enigma?"

Basically Churchill means to say "I don't know much about what Russia's gonna do"

Mysteries, riddles, and enigmas are all synonymous with "unknown".

So there's no telling what Russia's gonna do... trying to figure out what they're gonna do is like trying to answer an impossible question.

the second significant cause of the great migration was the desire of black southerners to escape segregation, known euphemistically as jim crow. rural african american southerners believed that segregation - and racism and prejudice against blacks - was significantly less intense in the north.

answer placeholder because the system is messed up