Question: Shanghai Tower is the world's third-tallest structure behind a building that reached its full height in which year ?
Sentence (from "Shanghai Tower"): It also has the world's highest observation deck within a building or structure (Level 121, 561.25 m), and the world's fastest elevators at a top speed of 20.5 m/s (74 km/h; 46 mph ).
Relevant evidence: No