問題詳情
【題組】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.
參考答案
答案：D
難度：適中0.587719
統計：A(77),B(53),C(51),D(268),E(0)
用户評論
【topbom】評論
. The big breakthrough of 3D printing took place in the early 2000s