Key developments on Aug. 3-4: Zelensky confirms F-16s already being used by Ukrainian Air ForceUkraine’s military says it sunk Russian Black Sea Fleet submarine, damaged S-400 missile system in ‘successful hit’Ukraine hit Morozovsk airfield, oil depots in Russia overnight, General Staff confirmsMilitary: Egyptians recruited by Russia fight in Kharkiv OblastOmbudsman appeals to UN, Red Cross over alleged execution of Ukrainian POW by RussiaPresident Volodymyr Zelensky confirmed on Aug. 4 that the first batch of F-16s had arrived in Ukraine and that the jets are already being used by Ukrainian p…