Part of the reason for having a Practice Quiz is so that you get used to the types of questions that might appear on a real quiz.


In Question #1 you should circle one word in each pair of words.  The resulting sentence, with your choices, should then be a correct statement. 
In Question #4 you must fill in the blanks because the order of the answers is important.  Filling in the first blank with b and the second blank with c wouldn't be correct.

In questions like #9 you can either fill in the blanks or circle the answers in the list.  This is because the order of the answers doesn't matter.

The top of the troposphere is, on average, around 10 km.  This is about 30,000 feet.  Thus the summit of Mt. Lemmon is in the bottom third of the troposphere, it's not even close to being in the stratosphere
.
Carbon monoxide emissions are trapped in thin surface temperature inversion layers.  Air temperature in an inversion increases with increasing altitude.  Surface inversion layers form above cold ground surfaces.  The ground is coldest in the winter and in the early morning.

You can think of the AQI as being a percentage.  An AQI value of 100 means the measured air pollution concentration is equal to the National Ambient Air Quality Standard for that pollutant.  An AQI value of 10 means the observed concentration is 10% of the NAAQS allowed value.  This would mean the air was pretty clean.


Pressure at any level in the atmosphere is determined by the weight of the air overhead.  Weight depends on mass and gravity.