Torrents and
Java Drive By's are the main two....
Just Google if you don't know exactly what they are..
so viruses dont spead :)
all of them
One way is for vaccinations. They use dead or weakened viruses to inject into people/animals so they can form immunities.
Certain poos
they can kill you
spead it
If people don't duck their heads the spead of the blades can cut their head off.
It depends on what you mean. If you mean types of viruses, there are:Virii,Trojans,and worms.
Rna and dna
viruses
Budding and Lysis.
water