What role did merchants from venice, italy play in the decline of the byzantine empire?

Which factor has played the most important role in changing the way history is studied over time?

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?

Why was there a crisis in the savings and loan industry? how much money was lost and who paid for it?