- 搜標(biāo)題
- 搜題干
- 搜選項(xiàng)
單項(xiàng)選擇題
The WWNWS establishes three types of navigational warning:（）.
A.Distress, Urgency and Safety
B.Vital, Important and Routine
C.NAVAREA, Coastal and local
D.gale, Tsunami and Ice
