Answer:
Water
Message me if you need a better explanation! :)
A. They impede fish migration and spawning
Answer;
I think it's d,possible spread of tropical diseases.
Answer: It is important to conduct many different experiments and estimates in a project for having as much statistic data as possible, because it is necessary to show proof on whichever project you are into. In order to avoid confusion, it's also possible to <u>organize data in Excel sheets/tables so it can be visually easier to interpretate</u>. <u>Gut instinct isn't enough to prove something wrong or righ</u>t, and <u>few data means higher probability of things going in ways other than the expected</u>.
