9.翻譯：遇險中繼信號已被確認。
(A)The DISTRESS-RELAY alert was transmitted.
(B)The DISTRESS-RELAY alert was confirmed.
(C) The DISTRESS-RELAY alert was acknowledgement.
(D)The DISTRESS-RELAY alert was received.

答案：登入後查看
統計： A(4), B(3), C(25), D(2), E(0) #1214635