小女儿又说：“我确定事情并不尽然——你没听见那声音吗？”

The youngest daughter said again, "I am sure all is not right—did not you hear that noise?"

youdao

或者，这只是一种“不高贵的回应”情况，我们也无法确定事情的真假。

Or it's a case of "won't dignify with a response" – we can't know for sure.

youdao

另一人写道。 三封邮件的语气都表示，她们有被迫做某种不确定事情的感觉，这使我深感不安。

The tone of all three emails was of feeling forced into something they weren't sure about, and it made me feel acutely uncomfortable.

youdao

The other thing I wanted to mention and I'm not sure if the exhibit's still there.

另外一个我想要指出的事情就是,我不确定它是不是还在展出。

麻省理工公开课 - 化学原理课程节选

A very common scenario, I'm sure.

我敢确定这是一个很司空见惯的事情。

留在记忆中的学生 - SpeakingMax英语口语达人

If you're stuck, if you're struggling, if you're not certain about something, please ask. We're not mind readers, we can't tell when you're struggling, other than sort of seeing the expression on your face, we need your help in identifying that.

如果你很差，如果你很纠结，如果你不确定某件事情，请问我们，我们不会读心术，我们没法儿看出来你们很纠结，除非能从你们的面部表情看出来，我们需要你们在这件事儿上的配合。

麻省理工公开课 - 计算机科学及编程导论课程节选