单项选择题 Considering the general circulation of the atmosphere，the wind system between latitudes 30°N and 60°N is commonly called the（）.

单项选择题 Consideration should be given in planning for the mooring orientation in a new location so that in adverse weather a crane is available to off-load the supply vessel on what side of the unit?（）

单项选择题 Concerning the identification signal for a pilot vessel，in fog，which statement is TRUE?（）