What was the aspect of American culture in the late 19th century was a major cause of the plexus of social problems that W. E.B Du bois refers to in the study of the negro problems

the answer. is b

hope this : d

the dust bowl, otherwise known as the dirty thirties, was a huge dust storm that killed multiple (and i mean  multiple) farmer's crops, leaving them homeless, and foodless, and jobless. in california, there were 5.7 million residents, and the population shrank as mexicans were repatriated. however, when the dustbowl happened, a lot of people began to move to california. by 1940, 250,000 people had arrived. therefore, your answer would be  the population increased, massively.  i hope this !

explanation:

a. theta waves. this is because the person is in a light sleep which means the brain waves would show these kind of waves.

adopted the practice of proskynesis, a persian court custom that involved bowing down and kissing the hand of others, depending on their rank.