The answer is letter
D.
<span>
Economists often use
the aggregate supply and demand model to reflect the total amount of goods and
services required at all possible price levels during a specific period. It
reflects the overall price of foods and services in an economy for a given
period and is often illustrated with the supply-demand curve. This shows the
relationship between price levels and quantity of output that a particular firm
is willing to provide to the general public.</span>
i believe the answer is 300. ;)
Explanation:
When using chromatography, the 2 solutes in the solvent paper should have different Rf values from the base line to identify them as different compounds.
If they were to have the same speed in the solvent, they would appear as 1 dot instead of 2 separate dots, which is a false reading.
It is d) to continue the species!!
hope this helps :)