Viruses are microscopic organisms that exist almost everywhere on earth. They can infect animals, plants, fungi, and even bacteria.
Sometimes a virus can cause a disease so deadly that it is fatal. Other viral infections trigger no noticeable reaction.
A virus may also have one effect on one type of organism, but a different effect on another. This explains how a virus that affects a cat may not affect a dog.
Viruses vary in complexity. They consist of genetic material, RNA or DNA, surrounded by a coat of protein, lipid (fat), or glycoprotein. Viruses cannot replicate without a host, so they are classified as parasitic.
They are considered the most abundant biological entity on the planet.
It is based on their state like population, literacy and poverty it varies from state to state, country to country
It is like that, except most nails are steel or stainless steel, slowing to rusting process to about 5 years.