1: About 3.8 billion years; they're bacteria-like organisms.
2: Adding salt to snow or ice increases the number of
molecules on the ground surface and makes it harder for the water to
freeze. Salt can lower freezing temperatures on sidewalks to 15
degrees from 32 degrees.
3: Influenza viruses and others continually change over
time, usually by mutation. This change enables the virus to evade the
immune system of its host so that people are susceptible to influenza
virus infection throughout their lives. Bacteria mutate in the same
way and can also become resistant if overtreated with antibiotics
Hope it helped
