Answer:
HIV crossed from chimps to humans in the 1920s 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
Explanation:
Google
The Transcontinental Railroad innovation had the GREATEST impact on westward migration immediately after the American Civil War.
After the Civil War, there was great interest and opportunity with westward expansion. With the invention of the railroad, the transport of goods and people became quicker and less expensive than ever before.
Gravitty is from the moon and it makes rain and snow fall
Several distinct cultural or ethnic groups within a society. Hope this helps!
