单项选择题
A.Red
B.Blue
C.Alternating red and blue
D.Purple
单项选择题 Navigational warnings and weather bulletins for shipping（）from Singapore Radio.
单项选择题 NASHA VERELLA ST JACQUES ZENMU ANSHA REEF CLOUDY TO OVERCAST WITH SHOWERS WIND SW 17 TO 21 SEA MOD VIS GOOD TO MOD.The abovementioned forecast is probably from（）.
单项选择题 Most high pressure areas are accompanied by（）.