阿摩線上測驗
129 By the time the technicians arrived, the problem _____ already been resolved.
(A) has
(B) have
(C) had
(D) having
答案：登入後查看
統計： A(182), B(35), C(446), D(7), E(0) #3772637
統計： A(182), B(35), C(446), D(7), E(0) #3772637
