阿摩線上測驗
19. During an earthquake, smoke alarms and sprinkler systems frequently ________ in building even if there is no fire.
(A) show off
(B) run off
(C) go off
(D) put off
答案：登入後查看
統計： A(63), B(107), C(95), D(32), E(0) #2310656
統計： A(63), B(107), C(95), D(32), E(0) #2310656
