I want to know the answer to the following question:
When was the latest addition to the facade at St Mark's Basilica in Venice?
All the background I'm provided with is that "Sometimes not only church interiors but façades were also decorated with mosaics in Italy like in the case of the St Mark's Basilica in Venice (mainly from the 17th–19th centuries, but the oldest one from 1270–75, "The burial of St Mark in the first basilica"), the Cathedral of Orvieto (golden Gothic mosaics from the 14th century, many times redone) and the Basilica di San Frediano in Lucca (huge, striking golden mosaic representing the Ascension of Christ with the apostles below, designed by Berlinghiero Berlinghieri in the 13th century).". Is that enough to answer the question?
Answer: yes