You need to answer this question because we don’t do homework and your teacher is looking for your critical thinking skills and how well you understood the lesson. He/she doesn’t want us to answer.
If you are talking about dual heating (front/rear), then either the rear temp control is set to cold, or the control is not working.
A cold front
The two most usual problems are 1- one or both of your front hubs are either bad or not engaged in the lock position. 2- check to see if you are getting power from your front driveshaft when the truck is in either 4 HI or 4 LOW. If both of these are good it is possible that you have a problem in your front differential or your transfer case.
A cold front usually causes the most violent weather
Cold
a front causes rain or a storm along the line where 2 masses meet they push against each other
i would consider them hands!
A cold front as this causes a lot of rain in a short period of time. A warm front causes light rain for days at a time.
It sounds like you may be having either Gall Bladder attacks or Heart burn .
Trench warfare limited territorial gains on either side.
Typically it's either raised too high or the suspension needs an alignment. Have you raised the vehicle? If so, that's the problem.