Why are streak plates used to test minerals? O A. They show you the silicon content of the mineral.
O B. They show you the true color of the mineral.
O C. They show you the color of the impurities in the mineral.

Babblers, a bird species, live in large cooperative groups. each member attempts to defend the group by sounding a loud bark-like call when it spots a predator, inciting the others to bark too. babblers, however, are extremely well camouflaged and could usually feed safely, unnoticed by predators. these predators, indeed, generally become aware of the presence of babblers only because of their shrill barks, which continue long after most members of the group have been able to take cover and which signal the group's approximate location to the predators. which one of the following, if true, would most to explain the babblers' strange behavior? (a) babblers fly much faster than the predators that prey upon them. (b) babblers' predators are generally intimidated by large numbers of babblers. (c) there is more than one type of predator that preys upon babblers. (d) babblers' predators have very good eyesight but relatively weak hearing. (e) animals that live in close proximity to babblers are also preyed upon by the predators that prey upon babblers.