 Complete the following phrase:  In December 2015 construction work on the exterior of the Curtis Green building was completed. On 31 October 2016, the Metropolitan Police staff left the building at 10 Broadway and moved to their new headquarters. The new New Scotland Yard building was to have been opened by Queen Elizabeth II on 23 March 2017, but that same day it was announced that the Royal opening would be postponed, due to the preceding days 