By Michael Butterworth
MACAO, Nov. 21 (Xinhua) -- Swiss-Italian racing driver Edoardo Mortara has hailed the unique challenge that racing in Macao represents.
Once a year, several of the city's streets are closed to the public and transformed into the Guia Circuit, a fearsome 6.2km facility whose combination of long straights, tight corners and elevation change make it one of the world's most challenging
