Group 1 - The article reports on the crash of two U.S. military aircraft in the South China Sea, with President Trump suggesting that fuel quality may be a factor in the incidents [1] - The U.S. Navy confirmed that an MH-60R Seahawk helicopter and an F/A-18F Super Hornet crashed after taking off from the USS Nimitz, with all crew members safely rescued [1][2] - China's Foreign Ministry expressed willingness to provide necessary assistance from a humanitarian perspective if requested by the U.S., while emphasizing that U.S. military activities in the South China Sea contribute to regional security issues [2]