GRE Text Completion: Manhatton-GRE填空Manhatton - 6ICX98Y53O12996A=

The famous Notre Dame cathedral in Paris took almost two hundred years to complete; this immense architectural effort included the first notable use of a flying ____________, but this renowned feature was not part of the original design and only employed when the walls forming the nave began to crumble and needed additional support. A. ballast B. albatross C. hallmark D. buttress E. trademark