1) The word "umbrella" contains three vowels: U, E, and A.

2) The first recorded car accident occurred in 1891 in Ohio.

3) The Nile River, spanning approximately 6,650 kilometers (4,130 miles), is the longest river in the world. It flows through eleven countries in northeastern Africa, supporting various civilizations throughout history and serving as a vital source of water and transportation.

4) The smallest unit of time is known as a zeptosecond, which is equal to one trillionth of one billionth of a second.