【单选题】Which of the following statements regarding VHF transmission is not true?
A.
VHF communications are effect.ive only with nearby stations within visual range.
B.
The height of vessel's antenna will affect the radius of propagation.
C.
The normal transmission range to a coast station is approximately 25 nautical miles.
D.
The frequency 156.525 MHz is designated for on-scene communication.
【判断题】三乙醇胺掺入混凝土中后,可加速水泥的水化,使早期生成的水化产物较多,相应地减少了毛细孔率,从而提高混凝土的抗渗性。 ()
【单选题】Believe in yourself and be _____ you are.
【单选题】合纵连横的倡导者中,六国的主要代表是( )。
【单选题】Which action should be taken on receipt of a GMDSS distress alert ________.
A.
Read the display screen and/or printout
C.
Listen for any follow up voice/telex transmission on the appropriate frequency
【单选题】Which information does the outer ring of a compass rose on a nautical chart provide? ______
D.
Annual rate of variation change.