Because there are so many strains, it is hard to pin point which strain needs to be treated.
A tissue.
Then a group of tissues that work together is an organ.
The a group of organs is an organ system.
A group of organ systems is and organism.
2 ways are 1 it can rise into the atmosphere or 2 it can be absorbed into the oceans.
Well part of the water cycle is evaporation which come from heat which you get from the sun. When the water evaporates it goes into clouds so then it can rain.
Hope this Helps