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

2) The book series "The Chronicles of Narnia" by C.S. Lewis has sold over 100 million copies worldwide.

3) The Hubble Space Telescope, launched in 1990, has provided breathtaking images of distant galaxies and deep space.

4) The fingerprints of koalas are so similar to humans that they have been mistaken at crime scenes.