Deciduous teeth important for the development of the child's speech, for the child's smile and play a role in chewing of food, although children who have had their primary teeth removed (usually as a result of Dental caries) can still eat and chew to a certain extent. In almost all European languages the primary teeth are called "baby teeth" or "milk teeth". In the United States and Canada, the term "baby teeth" is common. In some Asian countries they are referred to as "fall teeth" since they will eventually fall out. Various cultures have customs relating to the loss of deciduous teeth.
What Is and What Should Never Be and What Should Never Be" was performed live at Led Zeppelin concerts between 1969 and 1973. A live version taken from a performance at the Royal Albert Hall in 1970 can be seen on the "Led Zeppelin DVD". Another was included on disc two of the live triple album "How The West Was Won". Two more versions were included in BBC Sessions. What Is and What Should Never Be "What Is and What Should Never Be" is a song by English rock band Led Zeppelin. It was written by Jimmy Page and Robert Plant and was included as the second