Cold fronts cause thunderstorms as they pass by.
If cold air replaces warm air, it is called a cold front.
If cold air replaces warm air, it causes thunderstorms.
What does cold air replacing warm air cause?
Options:
* Greenhouse gases
* Pollution
* Dehydration
* thunderstorms
* steady barometer readings
* hypothyroidism
* constant air pressure
* stagnant air temperature