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>
Answer:
Rotation of Earth while orbiting the sun.
Answer:
White
Immune
Explanation:
White blood cells, also called leukocytes, are one of the cells that are involved in the body's immune system. They protect the body against various infections diseases and other invaders. Leukocytes are produced in the bone marrow (hematopoietic stem cells). They are not the only cells that are important for the defense of the body but are important.