1) The most-watched television event in the United States is the Super Bowl, with millions of viewers tuning in each year.

2) The concept of separation of powers, as articulated by French philosopher Montesquieu, refers to the division of government responsibilities into distinct branches, such as the executive, legislative, and judicial, to prevent concentration of power.

3) The Great Lakes, consisting of Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, form the largest group of freshwater lakes on Earth by total area. They are shared by the United States and Canada and are of significant ecological and economic importance.

4) The highest-grossing concert tour of all time is U2's "360° Tour," which earned over $735 million in ticket sales.