Answer:
It is a group designed to not be affected by any variables and to be used as a comparison to the other groups. It helps increase the reliability of your results, as it shows your independent variable is what made something happen in your experiment.
Dry climates do not have sufficient precipitation during the most of the year.
Desert are located in the arid climate.
The semiarid climate is in a grassland, or steppe, region.
3. naturally occurring
4. fossilized plants or air bubbles ( probably the plants tho)
5. increased
6. the green house effect occurs naturally, it is being polluted both naturally and unnaturally, the unnatural pollution is contaminating our 'greenhouse" and that is horrible.<span />