He is expected to be the key witness at the trial.

预计他将成为审判时的关键证人。

《柯林斯英汉双解大词典》

I finally found the right key after lots of trial and error.

经过反复试验，我终于找到了正确的方法。

youdao

Julio Lopez was a key witness from la Plata, who had played a significant role in the trial and life sentencing of Etchecolatz.

朱里诺·洛佩兹(Julio Lopez)是一名来自拉普拉塔的关键证人。他在艾切克·勒斯的审判和无期徒刑的判决中起到了关键的作用。

youdao

Schering-Plough has changed the start date listed in a government database for the key clinical trial testing the now-controversial cholesterol pill Vytorin, which Schering shares with Merck .

FORBES: Schering-Plough Backdates Trial

The questions raised by the president on this issue are legitimate, and demonstrate the need to call the key witnesses to the trial of this case, and to assess which version of the events is believable and substantiated by the corroborating evidence.

CNN

One of the last motions filed before the trial asked Judge Kaplan to put the key question of whether poker was a game of chance and therefore gambling before a jury, but Kaplan never ruled on this request.

FORBES: Federal Prosecutors Dodge Online Poker Trial By Handing Banker A Misdemeanor Deal