单项选择题 A（）is created by a pressure gradient or slope in the water level.

单项选择题 （）is the most widespread type likely to be encountered at sea and is caused by relatively warm air being cooled by flowing over a cooler sea surface.

单项选择题 （）is a type of fog occurring close to the sea surface when the air is dry and cold-probably at least 9℃ below the sea surface temperature.