In 2015, after fifteen years of development, the first F-35 squadron was released into active service in the United States Air Force.
In 2015, [M]after fifteen years of development, the first F-35 squadron was released into active service[/M] in the United States Air Force.[SEP]In 2015, after fifteen years of development, [M]the first F-35 squadron was released into active service in the United States Air Force.[/M][SEP][M]In 2015[/M], after fifteen years of development, [M]the first F-35 squadron was released into active service[/M] in the United States Air Force.