未知之事

例句：

1. 1.The scientist discovered a new species of plant that is yet to be identified.
   科学家发现了一种尚未被识别的新植物物种。
2. 2. The location of the lost treasure remains unknown to us.
   失落宝藏的位置对我们来说仍然是未知的。
3. 3. The identity of the culprit was unknown until the investigation was completed.
   直到调查完成，罪犯的身份仍是未知的。