阿摩線上測驗
49. Passengers are not allowed to open this window ______ there is an emergency.
(A)unless
(B)so that
(C)whereas
(D)as if
答案：登入後查看
統計： A(131), B(7), C(7), D(14), E(0) #2683374
統計： A(131), B(7), C(7), D(14), E(0) #2683374
