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(85), B(13), C(237), D(3), E(0) #3772637
統計: A(85), B(13), C(237), D(3), E(0) #3772637