(February 2014) Allusion is a figure of speech, in which one refers covertly or indirectly to an object or circumstance from an external context. It is left to the audience to make the connection; where the connection is directly and explicitly stated (as opposed to indirectly implied) by the author, it is instead usually termed a reference.
Titanium metal connects well with bone, so it has found surgical applications such as in joint replacements (especially hip joints) and tooth implants. The largest use of titanium is in the form of titanium(IV) oxide. It is extensively used as a pigment in house paint, artistsâ paint, plastics, enamels and paper.
Titanium is not a precious metal when you compare it to silver or gold, but if someone is shooting at you and you have a wall to stand behind that is made of Titanium is would be considered the most valuable item in your life. Titanium is light weight, very strong and is able to be made into different shapes. The cockpit of the US Air Force's A-10 (Warthog) is made of Titanium which will protect the Pilot and Co-Pilot/Navigator safe from being shot. I guess it all comes down to what you consider 'valuable'.