21. Which of the followings is not a proper means to maintain a proper look-out?
(A) By sight.
(B) By hearing.
(C) By echo sounder.
(D) By radar.

答案：登入後查看
統計： A(37), B(87), C(473), D(51), E(0) #2523271

詳解 (共 1 筆)

#5126749
題目意思是 以下哪一項不是保持適當瞭望...
(共 84 字，隱藏中）
前往觀看
8
0