Complex sentence: He fled Hong Kong in 1940 during the Japanese Invasion of China and ended up in San Francisco, California where he joined the US Air Force and learned English and served in both China and India until he could no longer serve due to war injuries.
Split into simpler sentences: He fled Hong Kong in 1940 during the Japanese invasion of China and ended up in San Francisco, California, where he joined the US Air Force and learned English. Wong served in both China and India until he was discharged due to war injuries.