 Complete the following phrase:  The armoured train Śmiały Polish for Bold, sometimes PP 53 and officially Armoured Train number 53 was an armoured train of the Polish Army that saw significant action during the German Invasion of Poland in September 1939. The train in the end served under four flagsAustrian, Polish, Soviet, Germanand fought in several wars from 1914 to 1945. Śmiały distinguished itself in the Battle of Mokra, after which it withdrew eastwards, taking part in the 