单项选择题
An atoll cloud forming over an island due to heating of the land during the daytime would be which type? （）
A.Cirrus B.Cumulus C.Stratus D.Nimbus
单项选择题 Advection fog is most commonly caused by（）.
单项选择题 Advection fog holds longest over which portions of the lakes? （）
单项选择题 According to Buys Ballot’s law，when an observer in the Northern Hemisphere experiences a northwest wind，the center of low pressure is located to the（）.
