Use of English PRO

Jimmy Morgan chose (0) THE Delta layout for its design and intended to fly at 3,200kph while carrying 270 passengers. Arnold Appleby called its design Swing Wings, which (1) ............ supposed to be (2) ............ to fly at 2,900kph, carry more than 270 passengers and have a flying range of (3) ............ than 6,700 kilometres. Concorde, meanwhile, had a top speed of 2,180kph and could carry just 128 passengers. On the 1st of January 1967, Appleby's design was chosen (4) ............ the winner but problems persisted. Some say engineers were trying to do too much and that so much of the technology needed to do this had not been properly developed. Kit Mitchell, the principal scientific officer at the then Royal Aeronautical Establishment (RAE) in the 1960s, has said "When we were building Concorde, we (5) ............ pushing technology as (6) ............ as it could possibly go at the time. They were pushing for something that was just (7) ............ difficult". So, was (8) ............ a step too far? In any case, the project became a victim of political turmoil, spiraling costs and environmental protests. Ultimately, neither of 'America's Concordes' ever flew.