In what year were euro banknotes and coins first introduced as cash?
In what year did the first Apple iPhone go on sale?
What is the exact speed of light in a vacuum, in metres per second, as defined in the SI?
How many bones are in the typical adult human skeleton?
What is the atomic number of gold?
How many planets are in the Solar System under the IAU's 2006 definition?
In what year was the Soviet Union dissolved?
In what year was the Bastille stormed, beginning the French Revolution?
In what year did World War II end?
In what year did Apollo 11 first land humans on the Moon?
In what year did the Berlin Wall fall?
How many players does each team have on the field at once in an association football (soccer) match, goalkeeper included?
How many men's professional major championships did Jack Nicklaus win?
In what year did Jackie Robinson make his Major League Baseball debut?
In what year were the first modern Olympic Games held?
How many Grand Slam singles titles did Serena Williams win in her career?
How many Wimbledon ladies' singles titles did Martina Navratilova win?