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

2) The word "guitar" contains three vowels: U, A, and I.

3) The fastest recorded serve in tennis was achieved by Sam Groth at 163.7 miles per hour (263.4 kilometers per hour) during a tournament in 2012.

4) The world's oldest tree is believed to be a bristlecone pine named "Methuselah" in California, estimated to be over 4,800 years old.