Complex sentence: Soon after graduating from a gymnasium in 1927, he joined the Infantry NCO School in Komorowo near Ostrów Mazowiecki where he was a mediocre student, neither receiving praise nor receiving censures, and completed his studies in 1928.
Split into simpler sentences: Soon after graduating from a gymnasium in 1927, he joined the Infantry NCO School in Komorowo near Ostrów Mazowiecki. Raginis was a mediocre student, did not receive praise, but did not receive censures and he completed his studies in 1928.