58. Which of the following structure is able to resist vertical pressure better?
(A)5ecb22c844303.jpg
(B)5ecb22f774c0b.jpg
(C)5ecb22df83816.jpg
(D)5ecb22e84229e.jpg

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統計: A(14), B(116), C(2), D(0), E(0) #2319582