1) 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.

2) The unicorn is the national animal of Scotland.

3) The Industrial Revolution, which began in the 18th century, brought about significant changes in agriculture, manufacturing, mining, and transportation.

4) The first sound film, "The Jazz Singer," was released in 1927 and marked the transition from silent movies to "talkies."