阿摩線上測驗
128. The factory has implemented strict safety protocols to prevent accidents_______heavy machinery operation.
(A) while
(B) during
(C) when
(D) as
答案：登入後查看
統計： A(82), B(312), C(56), D(73), E(0) #3823428
統計： A(82), B(312), C(56), D(73), E(0) #3823428
