1.Which of the following choices represent(s) a pair of resonance forms?
(A) both
(a) and
(b)
(B) both
(b) and
(c)
(C) both
(a) and
(c)
(D) All of the above
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統計: A(1), B(20), C(3), D(1), E(0) #3093892
統計: A(1), B(20), C(3), D(1), E(0) #3093892