3. Which of the following characteristics adds most to vertebrate success in terrestrial environments?
(A) the amniotic egg
(B) the ability to maintain a constant body temperature
(C) two pairs of appendages
(D) claws
(E) a four-chambered heart
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統計: A(123), B(14), C(3), D(2), E(9) #2069582
統計: A(123), B(14), C(3), D(2), E(9) #2069582