It is considering whether to issue iPhones but not sure it's necessary, noting that more than 700 iPhones were registered on the university's network last year.

该校正在考虑是否分发 iPhone，但不确定是否有必要。该校指出，去年该校网络上注册的 iPhone 超过700部。

youdao

I think this is their house, but I'm not sure.

我想这是他们家，但不敢肯定。

《牛津词典》

I would normally suggest taking time off work, but in this instance I'm not sure that would do any good.

我通常会建议休假，但就这个情况而言，我不敢保证休假会有什么好处。

《牛津词典》

The scientist says this mission has been planned for many years, but he is not sure when it will happen.

VOA: special.2010.05.25

You feel physiologically aroused but you're not completely sure why, and you have to make up an explanation for it.

你感觉到性觉醒,但是不能确定是什么原因，你不得不给出一个解释。

耶鲁公开课 - 心理学导论课程节选

I think they're about 17 and 5 or something like that or somewhere near that, not sure but

他们大概是17胜5负这样子，或者差不多，我不确定但

大学篮球的人气 - SpeakingMax英语口语达人

Interested in becoming a mentor but not sure how to get started?

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The end result of a debate such as what we experienced last week is that those not sufficiently afraid of Romney but still not sure they want him to be president will tend not to vote at all.

FORBES: Voter Enthusiasm Gap The Real Challenge To Obama Re-Election

Attracted to a stock with a fat dividend yield, but not so sure about the underlying company?

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