Why did many ancient civilizations in africa develop near bodies of water

Dalton developed the first model of the atom that showed the structure of the inside of an atom

President of the united states has scheduled a cabinet meeting today to discuss energy policy with specific focus on pollution and global warming. given what you know of the executive branch, which group of attendees would the president most likely expect to provide up-to-date information and expert insight during this meeting?

How did the us change it’s economy to provide supplies for the war effort?