 Complete the following phrase:  After heavy losses in Ukraine, the battalion was withdrawn to Vienna to refit. Starting on 2 January 1944 until April, the tank destroyers received upgradesthe most visible external ones being 1 the addition of Zimmerit anti-magnetic paste, 2 an upgraded commanders cupola, 3 re-designed armored engine grates and 4 an MG34 station to the right front of the hull. The 1st Company was issued the first 11 completed vehicles and was sent south to Italy where it fought at the 