It was already impossible to tell where the bullet had entered.

已经不可能判断子弹是从哪里射进来的。

《柯林斯英汉双解大词典》

It was impossible to tell from his mien whether he was offended.

从他的面部表情无法判断他是否生气了。

《柯林斯英汉双解大词典》

On cloudy days or at night it was impossible to tell the time with a sun clock or a sundial.

在阴天或晚上，无法用太阳钟或日晷看出时间。

youdao

"In recent years,these companies have become much more sophisticated, up to the point where it's impossible to tell the difference between the counterfeit cigarettes and the actual cigarettes."

VOA: standard.2010.08.11

It would be impossible to explain the entire debate, so we will just tell a few stories about some great artists.

VOA: special.2010.04.14

Cotton-industry officials say it is virtually impossible to tell organic cotton from the ordinary kind.

ECONOMIST: Ethically minded shoppers turn their focus to cotton

Whether Cheney really believes the insurgents are on their last legs is impossible to tell.

FORBES: Magazine Article

The rooms aren't labeled, and it's impossible to tell what's behind the scary mystery doors.

WSJ: Steam Heat, Vodka and a Sound Thrashing