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

2) The United States recently held its presidential election in 2020, resulting in Joe Biden being elected as the 46th President of the United States and Kamala Harris as the Vice President, making history as the first female Vice President.

3) The word "book" contains two vowels: O and O.

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