A cervical disc displacement occurs when there is a herniation or protrusion between discs in the spine. The bones that form the spine, referred to as vertebrae, feature discs between each bone to protect and allow for flexible movement of the back. One common phrase used when describing a cervical disc displacement is âslipped discâ.
Mass production is the period of 2nd industrial revolution which started with Ford cars around 1910. As you may be aware, now we are in the industry 4.0 period !! a year ago
1 (link). 2  Traces in detail the ideal of interchangeable parts, from its origins in 18th-century France, through the gradual development of its practical application via the armory practice (American system) of the 19th century, to its apex in true mass production beginning in the early 20th century.