Answer:
Stimuli is when an living organism responds back to what ha happened.
Explanation:
Culturing of microbial organisms allows experts to determine what type of organism is present and at what conditions it abundantly exist. This is an essential tool to determine the cause of contagious/infectious disease so that experts will have a clear understanding how to combat it.
Rerouting a river would likely affect the surrounding ecosystem and environment. Rivers are a powerful force in nature and effect everything from the shape of the terrain to the life around it.