1) 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.

2) The first modern Olympic marathon race was held at the 1896 Olympics in Athens and has since become one of the most iconic and challenging events in athletics.

3) The taco, originating from Mexico, is a versatile and flavorful dish enjoyed worldwide. It consists of a tortilla filled with various ingredients, such as seasoned meat, vegetables, cheese, and salsa. Tacos can be made with soft corn tortillas or crispy shells and can be customized with different toppings and fillings. They are a popular street food, casual meal option, and a symbol of Mexican culinary heritage and vibrant flavors.

4) Usain Bolt of Jamaica holds the world records for the 100 meters and 200 meters sprints, with times of 9.58 seconds and 19.19 seconds, respectively.