单项选择题
A sea breeze is a wind（）.
A.that blows towards the sea at night B.that blows towards an island during the day C.caused by cold air descending a coastal incline D.caused by the distant approach of a hurricane
单项选择题 A line of clouds，sharp changes in wind direction，and squalls are most frequently associated with a(n)（）.
单项选择题 A hygrometer is a device used for determining（）.
单项选择题 A generally circular low pressure area is called a(n)（）.
