Whether that result is positive or if is a flat result or something in between - something that we're not quite sure what it is - it is the first ever anti-retroviral containing product.

VOA: standard.2010.07.15

But you're not sure what it is, you can't put your finger on it.

你不清楚那是什么，你不能确定。

What kind of 课堂 - SpeakingMax英语口语达人

but I'm not sure what it is obviously.

但是我不确定到底是怎样的。

学生们的艺术热情 - SpeakingMax英语口语达人