Answer:
The correct answer is "decrease; negative".
Explanation:
If the pigeon changes its eating speed from VI 600-sec schedule to VI 100-sec schedule in the presence of the red key, most likely it will have the same effect in the presence of blue key. The rate of response of the VI 200-sec schedule in the presence of blue key will decrease. This change is known as a negative contrast effect, since the result lowers the eating speed of the pigeon.
Because it helps the ecosystem have clean water, it will help prevent floods from occurring, and will help with the natural production of crops and meats
I need to know what answers I can choose from
I believe the answer is a because the were the first organisms to colonize bare rock.