That was a silly thing to do !

那事做得蠢！

《牛津词典》

I regretted doing such a silly thing.

我后悔做了这样愚蠢的事。

youdao

That's not a silly thing to say about the astronomy case.

谈论这个天文学例子并不是什么傻事。

youdao

That's not a silly thing to say about the astronomy case.

谈论这个天文学例子,并不是什么傻事

耶鲁公开课 - 死亡课程节选

I know some of you come from Europe and other parts of the world where the ground floor is rez-de-chauss?e or some silly thing like this 1 and you push a button on the elevator to one and you go up to the first floor.

我知道你们中间有些人来自欧洲,或者世界其他地方，你们那里的一楼,和地面齐平，或者像这样可笑的事情,比如你要按下电梯的按钮,然后才能上到真正的1楼。

麻省理工公开课 - 固态化学导论课程节选

Obviously not, that would just be a silly thing to expect.

FORBES: The Glory That Is The French Economy

There's a term that's used in economics often as a derogatory term: fine tuning, in the sense that that's a silly thing to try because you can't achieve it.

NPR: Alan Greenspan and the Federal Reserve

It was a silly thing to be doing anyway.

FORBES: The European Union Will Not Subsidise Broadband. Hurrah!