Airport construction boomed during the 1960s with the increase in jet aircraft traffic. Runways were extended out to 3,000 m (9,800 ft). The fields were constructed out of reinforced concrete using a slip-form machine that produces a continual slab with no disruptions along the length. The early 1960s also saw the introduction of jet bridge systems to modern airport terminals, an innovation which eliminated outdoor passenger boarding. These systems became commonplace in the United States by the 1970s.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When was using reinforced concrete a common practice in the US?
Ah, so.. unanswerable

The disquilibrium and perceived corruption of the electoral and political process led, in 1966, to back-to-back military coups. The first coup was in January 1966 and was led by Igbo soldiers under Majors Emmanuel Ifeajuna and Chukwuma Kaduna Nzeogwu. The coup plotters succeeded in murdering Prime Minister Abubakar Tafawa Balewa, Premier Ahmadu Bello of the Northern Region and Premier Ladoke Akintola of the Western Region. But, the coup plotters struggled to form a central government. President Nwafor Orizu handed over government control to the Army, then under the command of another Igbo officer, General JTU Aguiyi-Ironsi.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Which Western Premier was murdered in the Igbo coup?
Ah, so.. Ladoke Akintola

Brasilia is known as a departing point for the practice of unpowered air sports, sports that may be practiced with hang gliding or paragliding wings. Practitioners of such sports reveal that, because of the city's dry weather, the city offers strong thermal winds and great "cloud-streets", which is also the name for a manoeuvre quite appreciated by practitioners. In 2003, Brasilia hosted the 14th Hang Gliding World Championship, one of the categories of free flying. In August 2005, the city hosted the 2nd stage of the Brazilian Hang Gliding Championship.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What air sports event did Brasilia host in 2003?
Ah, so..
the 14th Hang Gliding World Championship