What kind of work did enslaved africans mostly do in the north

Apsychologist has developed a series of personality inventories and wants to determine if they are valid. one of the scales measures perfectionism, so he asks a colleague for advice on how to establish the validity of this scale. the colleague tells him that if he were to find a sample of people with personality disorder, these people would obtain high scores on a scale that measures perfectionism.

Even before world war ii had ended, it was apparent that the allies would not remain friends in the post-war era. describe how the conflict between the superpowers manifested itself in the following region: europe.

What was different about warfare in the early 1800s and early 1900s?