1. National regulations banning supersonic speeds over land rule out trips across North America, home to lots of business travellers and most of the world’s business jets.

rule out 排除；取消

They didn't rule out coalition with the Social Democrats.

他们不排除与社会民主党人结盟的可能性FbivH.nc-k%-uX)gO。

2. Is this pie in the sky?

pie in the sky 虚无缥缈的承诺

He can't help thinking it's all just 'pie in the sky' talk.

他禁不住想所有这些不过是“画饼充饥”的空话而已EsSdf9lh)pUO3fZkLnj。