1) Mountains are important water sources, as they capture and store precipitation, feeding rivers and supporting ecosystems downstream.

2) The word "pencil" contains two vowels: E and I.

3) The Cuban Missile Crisis in 1962 brought the United States and the Soviet Union to the brink of nuclear war during the Cold War.

4) The game of basketball was invented by Dr. James Naismith in 1891 and has since grown into a global sport played at both amateur and professional levels.