 Complete the following phrase:  In 101 BC, the Cimbri returned to Gaul and prepared for the final stage of their struggle with Rome. For the first time they penetrated through the Alpine passes, which Mariuss co-consul for that year, Quintus Lutatius Catulus, had failed to fortify, into northern Italy. Catulus withdrew behind the Po River, leaving the countryside open to the invaders. But the Cimbri took their time ravishing the fertile region, which gave Marius time to arrive with reinforcements  his same victorious legions from Aquae Sextiae. It would be at 