单项选择题
The belt of light and variable winds between the westerly wind belt and the northeast trade winds is called the（）.
A.subtropical high pressure belt B.intertropical convergence zone C.doldrum belt D.polar frontal zone
单项选择题 The atmosphere in the vicinity of a high pressure area is called a(n)（）.
单项选择题 Prior to reading an aneroid barometer，you should tap the face lightly with your finger to（）.
单项选择题 Pressure gradient is a measure of（）.
