45 When did the major breakthrough of 3D printing take place?
(A) In the 1970s.
(B) In the 1980s.
(C) In the 1990s.
(D) In the 2000s.

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統計： A(148), B(77), C(74), D(634), E(0) #1269186

詳解 (共 2 筆)

#1588016

. The big breakthrough of 3D printing took place in the early 2000s
 

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#3016509

breakthrough突破

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