What nations troops entered berlin first at the close of the war?

Which fact would this be, and how might you verify the truth?

What stalled germany's initial invasion into france in 1914

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?