单项选择题
A.at a high rate of speed
B.under oars
C.against the wind
D.with the wind
单项选择题 A sufficient amount of chain must be veered when anchoring a vessel to ensure（）.
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（）.
单项选择题 A stretch where the channel changes from one side of the river to the other is called a （）.