Complex sentence: Salomon Mikhailovich Flohr (November 21,1908--July 18,1983) was a leading Czech and later Soviet chess grandmaster of the mid- 20th century, who became a national hero in Czechoslovakia during the 1930s.
Split into simpler sentences: Salomon Mikhailovich Flohr (November 21,1908--July 18,1983) was a leading Czech and later Soviet chess grandmaster of the mid 20th century. He became a national hero in Czechoslovakia during the 1930s.