The chosen valedictorian is often the student with the highest ranking among his/her graduating class. The term is an Anglicised derivation of the Latin vale dicere (to say farewell), historically rooted in the valedictorian's traditional role as the final speaker at the graduation ceremony.
The human body cannot survive without food and water for long periods of time. In fact, according to SurvivalTopics.com, the longest a person can go without water is 10 days--without food, it's four to six weeks.
Longest time without sleep Randy Gardner (born August 7, 1949) is the holder of the scientifically documented record for the longest a human has intentionally gone without sleep not using stimulants of any kind. In 1964, Gardner, a high school student in San Diego, California, stayed awake for 264.4 hours (11 days 25 minutes).