because a cold is a virus and not a bacteria.
Using kilometers in space is useless, as the distances between objects is drastically incred. A lightyear is 9.5 kilometers. It is simpler to say "Alpha Centauri is 4.1 light years away" than it is to say "Alpha Centauri is 28.95 Trillion kilometers away"<span />
Velocity is how fast the river is moving, the Volume is how much is in the river!
D. Man-Made is the answer
