If lack of moisture in the air causes low amounts of precipitation, then what causes low amounts of precipitation?

Answer choices:
- Plant growth is reduced
 - a hemisphere is tilted away from the sun
 - more condensation
 - extra moisture in the air
 - excess water supply
 - fissures of hot, acidic water
 - lack of moisture in the air
 - a tree falling

 

       lack of moisture in the air   