突然的问题让她措手不及，她说话结巴了。

The sudden question ___caught ___her ___off ___guard, and she stumbled over her words.

会议中意外的宣布让我措手不及。

The unexpected announcement ___caught ___me ___off ___guard during the meeting.

要在谈判中成功，你必须用聪明的策略让对方措手不及。

To succeed in negotiations, you must ___catch your counterpart ___off ___guard with a clever strategy.