That vision may take some time to come to fruition, as current US laws bar ultralights from flying over built up areas, but Martin said it would eventually become reality.

上述的一切可能需要一段时间才能实现，现有的美国法律禁止轻型飞行器飞跃建筑区，但是马丁说这一切最终会变成现实。

youdao

A speed limit of 30 mph was introduced in built-up areas.

在建筑物密集区域，限速为每小时30英里。

《柯林斯英汉双解大词典》

You must drop your speed in built-up areas.

在房屋密集区必须放慢速度。

《牛津词典》

But the violence spread through several built-up areas in and around the town.

FORBES: Myanmar's Ethnic Conflict Flares In Shadow Of Asian Oil Investments

Helicopter pilots in central London are instructed to follow the Thames, to avoid flying over built-up areas as far as possible.

CNN: London helicopter crash prompts safety questions

The survey had been "extremely well supported... even in the most built-up areas where you might not expect people to watch birds, " Mr Bashford added.

BBC: NEWS | UK | Fewer birds spotted in UK gardens