He's up to something or other.

他在做某种事。

youdao

Tom's been smiling to himself all morning. I think he's up to something, but I don't know what it is.

汤姆整个上午都在窃笑，我想他肯定没什么好事，但就是不知道是什么事。

youdao

So Milton implies to Diodati that he isn't yet up to the task of epic, but as he describes the Nativity Ode that he's just written, it's almost as if he considers it something of a mini-epic.

所以弥尔顿暗示迪奥达蒂自己还不能完成创作史诗的任务，但他提到了他刚写完的《圣诞清晨歌》,好像这就是一篇迷你史诗。

youdao

So he's up to something here with this rate of harmonic change.

他在这里准备做一点什么，泛音的速度发生了变化。

耶鲁公开课 - 聆听音乐课程节选

She said her father's friends thought he might have reached forward to pick something up from the floor and encountered turbulence which flipped his aircraft over.

BBC: Essex

But von Lipinski's wife knew something was wrong when he kept getting up during the night, unable to sleep because of the pain.

CNN: Surviving a flesh-eating disease

National Rail's regional route managing director Martin Frobisher said he hoped it would be possible to put something up "within a few short months".

BBC: Lindsey Inger tram death: Temporary footbridge announced