Answer: <span>Normal microbiota directly kill invading organisms.
Some bacteria that reside in our body are useful to combat pathogenic microorganisms. Those bacteria, like lactobacillus and E.coli, inhibit the growth of those pathogenic organisms by taking, for example, oxygen and nutrients from them, or even changing the local ph. They can also produce metabolites that make the environment impossible to live for the intruders.
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I looked it up and got biotic.<span />
Answer:
1. Global warming is the change in the climate of the earth causing it to heat up whereas the greenhouse effect is a naturally occurring phenomena, constantly occurring due to the atmosphere and sunlight.
2. Carbon dioxide absorbs heat radiating from the Earth's surface and re-release it in all directions—including back toward Earth's surface.
3. Decomposition, ocean release and respiration.