单项选择题
A.expose any loose connections B.demagnetize the metal elements C.bring the pointer to its true position D.contract and expand the glass face
Pressure gradient is a measure of（）.A.a high-pressure a...
单项选择题Pressure gradient is a measure of（）.
A.a high-pressure area B.pressure difference over horizontal distance C.pressure difference over time D.vertical pressure variation
On what does the operation of an aneroid barometer depe...
单项选择题On what does the operation of an aneroid barometer depend?（）
A.Thin，metal，air tight cell B.Curved tube containing alcohol C.Column of mercury supported by atmospheric pressure D.Expansion of mercury in a closed tube
MODERATE WAVES，TAKING A MORE PRONOUNCED LONG FORM；MANY ...
单项选择题MODERATE WAVES，TAKING A MORE PRONOUNCED LONG FORM；MANY WHITE HORSES ARE FORMED.THIS sea condition is likely to be termed（）.
A.moderate breeze B.fresh breeze C.strong breeze D.near gale
