Original sentence: It is assumed that the rest of the series is destroyed, due to a common network practice known as wiping; ABC, specifically, continued this practice until 1978.Only the pilot (taped February 10 with Gillette and Sales) and the Premiere (taped April 4 with Meara and Shatner) are known to exist
Edited sentence: Only the pilot (taped February 10 with Gillette and Sales) and Premiere (taped April 4 with Meara and Shatner) are known to exist.The series is believed to have been destroyed as per network practices of the era (ABC, specifically, continued this practice until 1978)