1) The word "country" contains three vowels: O, U, and Y.

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

3) Many mountains have cultural and spiritual significance for local communities and are often considered sacred or revered in religious traditions.

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