B. atmosphere since the atmosphere is made up of o2, co2 (a greenhouse gas) and nitrogen. those are the primary elements
Viruses are even smaller than bacteria and require living hosts — such as people, plants or animals — to multiply. Otherwise, they can't survive. When a virus enters your body, it invades some of your cells and takes over the cell machinery, redirecting it to produce the virus.
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6. Which of the following is a step that occurs within an inflammatory response?
