sentences:  In 1920, Duff began his racing career at Brooklands, a 2.6 mile long concrete track with concave banking.He drove a Fiat S.61, a 10-litre chain-driven car built in 1908.By August 1920, he was lapping in the same range as Henry Segrave, one of the great Brooklands and Grand Prix drivers of the 1920s.