The heart, liver, and stomach are each examples of
a. a tissue.
b. an organ.
c. an organ system.
d. a nerve.

Common symptoms of an iron-defiency anemia include muscle weakness shortness of breath and lightheadedness why does iron deficiency causes these symptoms

Warmer ocean surface water would most likely be found near

Achemical that is released by an animal as a signal to other members of the same species is called a pheromone. t or f