47. Which of the following vertebrates is first characterized by the presence of an amniotic egg?
(A) amphibians
(B) fishes
(C) reptiles
(D) mammals
(E) chordates
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統計: A(6), B(0), C(41), D(3), E(1) #3224828
統計: A(6), B(0), C(41), D(3), E(1) #3224828