单项选择题
（）LOW ELY SLWLY WITH COLD FRONT FM CEN TO 12N 179W AND WARM FROM FM CEN TO 11N 171W.
A.SHLW B.SCTD C.OBS D.SW
单项选择题 The Routing System which aimed at reducing the risk of casualties is called as（）.
单项选择题 When winds of force reach 10-11 in Beaufort Scale，usually we call such winds as（）.
