Answer:
Relationship Between Diameter and Circumference
If you know a circle's diameter, you can calculate its circumference with this equation: Circumference = diameter times pi (3.14).
<span>The immune system is the body's natural defense mechanism against organisms that can cause infection.There are three types of mechanisms:
1. Cellular :</span><span> refers to the recognition and/or killing of virus and virus-infected cells by leukocytes and the production of different soluble factors (cytokines) by these cells when stimulated by virus or virus-infected cells
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2. Structural: </span>barriers and the immune system defend the body<span> against organisms that can cause infection. </span>Natural<span> barriers include the skin, mucous membranes, tears, earwax, mucus, and stomach acid.
3. Chemical: </span><span>Some of these include the low pH of the stomach, which inhibits the growth of pathogens; blood proteins that bind and disrupt bacterial cell membranes; and the process of urination, which flushes pathogens from the urinary tract.
</span><span>antibodies - chemical
tissues lining hollow organs - cellular
phagocytes - cellular
skin - structural
antigen - chemical
leukocytes - cellular</span>
Answer is c. Natural gas.
Natural gas is a fossil fuel in liquid form that can be used as an energy source. It is found in subterranean reservoirs, often near oil deposits. It is non-renewable energy source. It takes very long time to renew. Natural gas is less pollutant as compared to coal and petroleum because when it's burned, it releases 25 % fewer greenhouse gases and pollutants. hydroelectric power, solar power and nuclear energy are renewable sources.
this is true. when it is warmer the plant and insects can migrate to these other places so they do not have to die or hibernate through winter