单项选择题
An instrument designed to maintain a continuous record of atmospheric pressure is a(n)（）.
A.mercurial barometer B.aneroid barometer C.barograph D.thermograph
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? （）
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? （）
