He said the planned attack, which could have killed many people, was not proportionate to Iran's downing of an unpiloted drone.

特朗普表示，打击计划可能会导致很多人死亡，而如果导火索只是一架无人机话，就不偿失了。

If Boeing's unpiloted test goes well, the company is expected to move ahead with its first crewed test flight of Starliner.

如果波音无人驾驶测试进展顺利，该公司将推进其船首载人试。

The Air Force said it hopes the system it is working on today can be used to create a fleet of 1,000 unpiloted airplanes.

空军表示，希望今天正在研发系统可以用来创建一支1000架无人驾驶机机队。