阿摩線上測驗
28. By the time the first speaker went live, the technician _____ the audio check and had left the control booth.
(A) completes
(B) are completing
(C) had completed
(D) have completing
答案：登入後查看
統計： A(0), B(1), C(10), D(1), E(0) #3895751
統計： A(0), B(1), C(10), D(1), E(0) #3895751
