B) Circulatory.
The Circulatory system spreads the blood all around the heart. It makes sure blood is able to reach every part in the body.
C - By exhaling/ breathing out
Retroviruses store their genetic information in molecules of ribonucleic acid (RNA). However, unlike other RNA viruses, retroviruses use RNA as a <span>template </span>for forming deoxyribonucleic acid. <span>Viral genetic replication, especially in the case of retroviruses, have few, if any, error-checking mechanisms, which results in a high rate of mutation.</span>
There is no set lifespan.It can live as long as the environment can support its life. However the average lifespan differs for each particular species, with an average life expectancy from a few days to a year or two.
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The best fit line "minimizes the distance from the points to the line".
<u>Option: C</u>
<u>Explanation:</u>
A best fit line is a straight line that best showed the information on a scatter plot. It can traverse all points or none of the points or some of the data points. On scatter plot the set of points to be distributed along any axis, which may or may not look. When a linear pattern occurs, it becomes essential to plot a line of best fit that significantly reduces the distance of those points from that line to help us predict the values that are not shown on the scatter-plot.