单项选择题
A.blue line B.purple line C.dashed blue line D.alternate red and blue line
An aneroid barometer is an instrument（）.A.used to measu...
单项选择题An aneroid barometer is an instrument（）.
A.used to measure the speed of wind B.in which the pressure of the air is measured C.that tells which direction a storm is coming from D.used to measure the height of waves
An air mass is termed warm if（）.A.it is above 70°FB.the...
单项选择题An air mass is termed warm if（）.
A.it is above 70°F B.the ground over which it moves is cooler than the air C.it originated in a high pressure area D.it originated in a low pressure area
All of the following are associated with cumulonimbus c...
单项选择题All of the following are associated with cumulonimbus clouds EXCEPT（）.
A.steady rainfall B.hail storms C.thunderstorms D.tornadoes or waterspouts
