&hint2=When reinforced with concrete, I am the basic component for massive structures&
&hint3=When put next to others like me, I form an arcade&
&hint4=I am one of the best-known examples of a very large version of the common form of amphitheater&
&choices=Pantheon, interior;The citadel and palace complex of Sargon II;Bayeux Tapestry, detail of Ubi Harold Sacramentum Fecit;Colosseum;Equestrian statue of Marcus Aurelius;Codex Aureus of St. Emmeram&