A forerunner of those vehicles, though, is already being developed and tested.
A forerunner of those vehicles, though, is already being developed and tested.
不过这类飞机的先驱机型目前已在开发及测试中。
A forerunner of those vehicles, though, is already being developed and tested.
不过这类飞机的先驱机型目前已在开发及测试中。