中央空调系统在主机正常供冷的情况下发现个别盘管风机出风不冷，可能是什么原因？有何方法解决

A. reduce the navigational workload compared to using the paper chart
B. enable mariner to execute in a convinient and timely manner all route planning, route monitoring and positioning currently performed on paper charts
C. be able to plot ships position continuously and automatically
D. be used for the display of radar, radar tracked target information, AISand other appropriate data layers to assist in route monitoring