Complex sentence: Three thousand Hezbollah militants have undergone training in Iran, which included guerilla warfare, firing missiles and rocket artillery, operating unmanned drones, marine warfare and conventional war operations, and 50 pilots have been trained in Iran in the past two years.
Split into simpler sentences: Three thousand Hezbollah militants have undergone training in Iran, which included guerilla warfare, firing missiles and rocket artillery, operating unmanned drones, marine warfare and conventional war operations. Finally, 50 pilots have been trained in Iran in the past two years.