2 sentences

1. 我不清楚，对不起。

   wǒ bù​qīng​chu, duì​bu​qǐ.

   I don't know, I'm sorry.

   Source: OpenSubtitles

2. 不清楚是否还有其他人参与。

   bù​qīng​chu shì​fǒu hái​yǒu qí​tā rén cān​yù.

   It is unclear if anyone else was involved.

   Source: CCMatrix