=Introduction= A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links.
=Challenges= <youtube>FZN0PBBzEHw</youtube>
=Approaches= <youtube>y3Vb19QE6iI</youtube> <youtube>ljCrxoLiPcY</youtube>
=References=