单项选择题
A strong，often violent，northerly wind occurring on the Pacific coast of Mexico，particularly during the colder months，is called（）.
A.Tehuantepecer B.Papagayo C.Norther D.Pampero
单项选择题 A stretch where the channel changes from one side of the river to the other is called a （）.
单项选择题 A storm’s track is characterized by all of the following except（）.
单项选择题 A stand-on vessel is（）.
