Answer:
White dwarfs have an extremely small surface area to radiate this heat from, so they cool gradually, remaining hot for a long time.
Explanation:
As a white dwarf cools, its surface temperature decreases, the radiation which it emits reddens, and its luminosity decreases.
Answer:
B. Organ system
Explanation:
Cells are the smallest level of organization. They make tissues and tissues make organs like heart and lungs. Organs make organ systems which are the highest level of organization such as respiratory system which includes organs like lungs etc.
Answer:
Limilus and L. pilyphemus
Explanation:
Atlantic horseshoe crab.
