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

2) The world's largest volcano, Mauna Loa in Hawaii, is also one of the most active. It stands over 13,000 feet (4,000 meters) above sea level.

3) The world's first stock exchange was established in Amsterdam in 1602.

4) The word "table" contains two vowels: A and E.