Complex sentence: An early version shows some civic functions, called by the architect the "Citadel of the Institutions," grouped opposite the assembly, but none of its constituents was ever built, and in 1971 it was replaced by the National Secretariat of Bangladesh.
Split into simpler sentences: An early version shows some civic functions, called by the architect the "Citadel of the Institutions," grouped opposite the assembly. None of its constituents was ever built and, in 1971, it was replaced by the National Secretariat of Bangladesh.