I didn't know what else to say.

我不知道还能再说点什么。

《柯林斯英汉双解大词典》

I don't know what to say.

我不知道说什么好。

《牛津词典》

I do not know what to do with the information if I cannot pass it on.

如果无法传送出去，我不知道该拿这情报怎么办。

《柯林斯英汉双解大词典》

I do not know what else to do but make the best of a bad deal and shake hands over it."

VOA: special.2009.06.27

The very fact that I need to know it in particular is what makes me need to know it negatively.

认识一件事物需要知道,它不是什么。

耶鲁公开课 - 文学理论导论课程节选

I chose English Literature because when I started off a university, I didn't know what it was I wanted to do.

我选英语文学是因为当我刚上大学的时候，我不知道自己到底想做什么。

为何选那门专业？ - SpeakingMax英语口语达人

I'm not going to get into the specific intelligence, though, of this, except to point you to what I know that has been said publicly at the Pentagon today.

WHITEHOUSE: Press Briefing

Before I say anything else, I want to echo what I know Hillary addressed earlier -- just say a few words about our friend and partner, Richard Holbrooke.

WHITEHOUSE: Diplomatic Corps Holiday Reception

"I started to realize the amount of time I was spending trying to compensate for the fact that I didn't know what investments needed to be made, and I didn't have the pattern recognition to know what was coming around the corner, " he says.

WSJ: When It's Time for a Small Business to Bring in a Professional CEO