Complex sentence: During the Great Patriotic War Zhemchuzhina actively supported Jewish Anti-Fascist Committee (JAC) and befriended many of its leading members, most notably Solomon Mikhoels and frequently attended performances by Moscow State Yiddish Theater.
Split into simpler sentences: During the Great Patriotic War Zhemchuzhina actively supported Jewish Anti-Fascist Committee (JAC) and befriended many of its leading members, most notably Solomon Mikhoels. She frequently attended performances by Moscow State Yiddish Theater.