 Complete the following phrase:  In 1953, the FIA World Sportscar Championship was introduced. The Targa became part of it in 1955, when Mercedes had to win 1-2 with the Mercedes-Benz 300 SLR in order to beat Ferrari for the title. They had missed the first two of the 6 events, Buenos Aires and the 12 Hours of Sebring, where Ferrari, Jaguar, Maserati and Porsche scored. Mercedes appeared at and won in the Mille Miglia, then pulled out of Le Mans as a sign of respect for the victims of the 