Q631: The Three Sisters rivers are located in which country?
Q632: Mount Mitchell is located on which mountain range?
Q633: Which country did sign CTBT?
Q634: Which athlete has won the most Olympic medals in history?
Q635: The man who built the first Mechanical Calculator was ______?
Q636: What is the traditional underground water system (Karez) in Iran called?
Q637: Which is the deepest trench in the Atlantic Ocean?
Q638: When was the League of Nations formed?
Q639: The Blue Mosque or the "Mosque of Sultan Ahmed" is located in _____?
Q640: A standard 400 Meters Oval track typically has ___ lanes.