試題詳解

50. Why are big, predatory animals rare?
(A)they are highly territorial.
(B)it takes a long time for big, predatory animals to evolve.
(C)It’s hard for a big animal to move through dense vegetation.
(D) It’s hard for an ecosystem to support many of them because so much energy is lost at each level of energy exchange.
(E)overexploitation by humans has caused many predatory species to become endangered.