Hi !
<em />
<em>Her memory for the start of her list demonstrates the </em>"primacy" <em>effect, while remembering things at the end of the list is an example of the </em>"recency" <em>effect.</em>
HIV crossed from chimps to humans in the 1920's in what is now the Democratic Republic of Congo. This was probably as a result of chimps carrying the Simian Immunodeficiency Virus (SIV), a virus closely related to HIV, being hunted and eaten by people living in the area.
I think rotation?
sorry if it doesn't help i'm not entirely sure