Answer:
Virulence, the capacity to cause disease, varies markedly among viruses. Some viruses cause lethal disease while others do not. For example, nearly all humans infected with rabies virus develop a disease of the central nervous system which ultimately leads to death. In contrast, most humans are infected with circoviruses with no apparent consequence.
Explanation: One explanation for viral virulence is that it facilitates transmission. However, a comparison of infections caused by two enteric viruses, poliovirus and norovirus, does not support this general view. Both viruses infect the gastrointestinal tract and are spread efficiently among humans by fecal contamination.
The imaginary line the circles earth, halfway between the North and South Poles is called the equator. It pretty much cuts the globe in half. The top half is called the Northern Hemisphere. The bottom half is called the Southern Hemispere.
A. Water to move into the cell
