Add punctuation: The remains of the coliseum became home to a family of sharks
A: The remains of the coliseum became home to a family of sharks.

Add punctuation: In order to find the axis of symmetry we took the factor 2 outside a bracket
A: In order to find the axis of symmetry we took the factor 2 outside a bracket.

Add punctuation: With the successful return from this voyage around the world in December 1980 even Londons famous Tower Bridge was opened fully
A:
With the successful return from this voyage around the world in December 1980 even London's famous Tower Bridge was opened fully.