阿摩線上測驗
130. Please ensure that all confidential documents are shredded _______ placing them in the recycling bin.
(A) upon
(B) while
(C) formerly
(D) before
答案：登入後查看
統計： A(6), B(19), C(8), D(134), E(0) #3804688
統計： A(6), B(19), C(8), D(134), E(0) #3804688
