飞艇、旋翼飞机、气垫船，这些交通工具都能运行，甚至也有合适的应用领域，但它们的表现总是差强人意，从未得到大规模地应用。

Airships. Autogyros. Hovercraft. They all work. They even have niche applications. But they have never lived up to their promise and been widely adopted.

youdao

让直升机在头顶悲旋，在天空书写他已逝去的消息，把黑纱系在信鸽的颈项，让交通警察戴上黑色的手套。

Let aeroplanes circle, moaning overhead, Scribbling on the sky the message: He is Dead. Put crepe bows 'round the necks of public doves, Let trafficpolicemen wear black, cotton gloves.

youdao