Question

which phrase best describes humidity?
the amount of precipitation that falls
the temperature of air that causes condensation
the amount of water vapor in the air
the condensation that forms on a cooler surface

Explanation:

Humidity is defined as the amount of water vapor present in the air. Precipitation is water falling from the atmosphere (rain, snow, etc.), so the first option is incorrect. The temperature of air that causes condensation is the dew - point temperature, not humidity, so the second option is wrong. Condensation on a cooler surface (like dew on grass) is a result of humidity but not the definition of humidity itself, so the fourth option is incorrect.

Answer:

the amount of water vapor in the air