You are presented with the question "A lack of moisture in the air causes low amounts of what?" and the following answer choices: 
- harmful substances
 - Calcium carbonate
 - flooding
 - heat
 - desert
 - fossil fuels
 - nutrients
 - precipitation

Now knowing that lack of moisture in the air causes low amounts of rainfall and rainfall is just one form of precipitation, choose the best answer.


 

        precipitation 