Black
While in olden days gondolas could be many different colors, but sumptuary law of Venice required that gondolas should be painted black.
In quantum mechanics and particle physics, what is the usual term for an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei?
What type of building is famous in Milan, Venice, Florence, Seville, Paris, Chartres, Amiens, Rheims, Cologne, Mainz and Trèves?