问题
单项选择题
（）is the most visible signal of distress from a lifeboat at sea in the daytime.
A.Smoke signal
B.Flash signal
C.Fire signal
D.Radio emergency transmission
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
（）is the most visible signal of distress from a lifeboat at sea in the daytime.
A.Smoke signal
B.Flash signal
C.Fire signal
D.Radio emergency transmission
参考答案：A