单项选择题
A.high relative humidity
B.frequent showers and thunderstorms
C.steep pressure gradients
D.frequent calms
单项选择题 In the northern hemisphere, the largest waves or swells created by a typhoon or hurricane will be located().
单项选择题 In weather report, position good means that().
单项选择题 In which voyage, between two points, is the rhumb line distance not approximately the same as the great circle distance?().