The walls of the Taj Mahal are inlaid with semiprecious stones in a mosaic technique called pietra dura that the Moguls learned from the

Which building material creates almost limitless possibilities for construction?

a. Stone b. Steel c. Wood d. Precast concrete

A round arch consists of __________.

A. arcades and buttresses B. voussoirs and a keystone C. aisles and an apse D. coffers and a clerestory