Task: Question Generation
Input (English): Passage: Lake Burley Griffin is crossed by Commonwealth Avenue Bridge (310 metres or 1,020 feet), Kings Avenue Bridge (270 metres or 890 feet) and a roadway over Scrivener Dam. The two bridges were constructed before the lake was filled, and replaced wooden structures.
Site testing for both the Commonwealth Avenue and Kings Avenue bridges took place during late 1959 to early 1960. The construction of the Kings Avenue Bridge began in 1960, followed by Commonwealth Avenue Bridge the year after. Fortunately for the builders, Canberra was in a drought and the ground remained dry during construction. Both bridges use post-tensioned concrete, reinforced with rustproof steel cables.Both bridges are made of concrete and steel and are dual-carriageway; Commonwealth Avenue has three lanes in each direction while Kings Avenue has two. Instead of traditional lamp post lighting, Kings Avenue Bridge was illuminated by a series of fluorescent tubes on the handrails, a concept known as "integral lighting". The design was deemed a success, so it was introduced to the Commonwealth Avenue Bridge also. Both structures won awards from the Illumination Engineering Society.Kings Avenue Bridge opened on 10 March 1962. Prime Minister Menzies unlocked a ceremonial chain before the motorcade and pageant crossed the lake in front of a large crowd. Commonwealth Avenue Bridge opened in 1963 without an official ceremony. Menzies called it "the finest building in the national capital".
Output (English): What are the names of the two structures that were constructed before the lake was filled?