Complex sentence: The east front, towards the street, has a portico in the Tuscan order, with a central arch cutting through the entablature and pediment--a motif used in Wren's "Great Model" for St Paul's Cathedral.
Split into simpler sentences: The east front, towards the street, has a portico in the Tuscan order. A central arch cuts through the entablature and pediment--a motif used in Wren's "Great Model" for St Paul's Cathedral.