mystery中等

mysteries

谜团

But where and when these animals first became intertwined with humans has been a mystery.

但这些动物最初是在何时何地与人类产生密切联系的，一直是个谜。

How the whole image is then assembled and perceived is still a mystery although it is the subject of current research.

至于整个图像随后是如何被组合和感知的，尽管这是当前的研究课题，但仍然是个谜。