单项选择题
The atmosphere in the vicinity of a high pressure area is called a(n)（）.
A.anticyclone B.cold front C.occluded front D.cyclone
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（）.
单项选择题 On what does the operation of an aneroid barometer depend?（）
