 Complete the following phrase:  After Operation Barbarossa began, the 54th Tank Division covered the Soviet border in the Transcaucasus. In late July and early August the 28th Mechanized Corps was used to form the 47th Army. Colonel Sinenko led the division in the Anglo-Soviet invasion of Iran in August. In October he was appointed commander of the 55th Tank Brigade, which joined the Transcaucasian Front. From January 1942 the brigade fought in fierce fighting in the 