What are the economic, environmental and social benefits of creating dams

Sam and ben have discovered some strange animals living in the woods behind their house. ben is excited because he believes they are marsupials, an animal he's never observed in the wild before. his brother is sure it is not. what feature should the boys consider in deciding whether the animals are marsupials?

How the environment of the northeast region affects the lifestyle of the people that live there

Are people more motivated to change from positive or negative experiences, like slavery, womens rights, and any other historical movements/moments? i need more factual information than opinions.