Complex sentence: He graduated from the Etajima Naval College in November 1917, and then went to the Torpedo School in Yokosuka Naval Station, and later specialized in submarines, becoming commander of the 20th Submarine Division in November 1939.
Split into simpler sentences: He graduated from the Etajima Naval Academy in November 1917, and then went to the Torpedo School at the Yokosuka Naval Arsenal. He later specialized in submarines, and became commander of the 20th Submarine Division in November 1939.