1) The concept of gravity was famously described by Sir Isaac Newton after an apple fell on his head.

2) The Rocky Mountains, also known as the Rockies, extend from Canada through the United States, offering stunning landscapes and outdoor recreational opportunities.

3) The concept of self-driving cars, or autonomous vehicles, is being actively developed by companies such as Tesla, Google (Waymo), and Uber.

4) Political campaigns involve strategic activities, such as advertising, public appearances, and grassroots organizing, aimed at promoting a candidate or political party and gaining support during elections.