This took place just after the United States completed of the Louisiana Purchase. They explored the western United States beginning in Missouri through the Mississippi to the Pacific coast. John Smith (c.1580-1631) Famous For: Exploring Virginia and Chesapeake Bay rivers
Video on demand (display) (VOD) are systems which allow users to select and watch/listen to video or audio content such as movies and TV shows when they choose to, rather than having to watch at a specific broadcast time, which was the prevalent approach with over-the-air broadcasting during much of the 20th century.
Volatile organic compounds, or VOCs are organic chemical compounds whose composition makes it possible for them to evaporate under normal indoor atmospheric conditions of temperature and pressure. This is the general definition of VOCs that is used in the scientific literature, and is consistent with the definition used for indoor air quality.