Short answers, pulled from the story.
Ctibor Novák planted explosive devices in Berlin on the 15th of September 1939. His bombs detonated near the Ministry of Aeronautics and police headquarters causing damage and injuries to many Germans.
Witold Pilecki entered Auschwitz concentration camp on the 19th of September 1940 using a false identity card provided by the Polish Home Army. He organized Związek Organizacji Wojskowej inside the camp to send genocide reports back to Home Army Headquarters starting in October 1940.
Yugoslav resistance fractured between royalist Chetniks who sometimes collaborated with Nazis until July 1941 and communist Partisans led by Josip Broz Tito. This ideological divide created complex relationships where former allies became enemies overnight.
Axis forces rallied 127,000 troops including German Italian NDH Bulgarian and Cossack units plus over 300 airplanes against 18,000 Yugoslav Partisans organized into 16 brigades. The Partisans succeeded in breaking out across the Sutjeska river toward eastern Bosnia despite severe food shortages and typhoid outbreaks among their ranks.
Norwegian saboteurs ended Nazi nuclear ambitions on the 20th of February 1944 by bombing the ferry SF Hydro carrying heavy water drums from Vemork hydroelectric plant. Their sinking effectively stopped German progress on atomic weapons development.