adj.原因不详的，未解释的，未说明的

The disappearance of the ancient civilization remains an unexplained mystery.
这个古代文明的消失仍然是一个未解之谜。
There were unexplained bruises on her arms, which raised concerns.
她的手臂上有些无法解释的瘀伤，这引起了担忧。
The sudden termination of the project was unexplained, leaving many questions unanswered.
项目突然终止的原因未被说明，留下了许多未解的问题。
The witness's account of the event contained several unexplained gaps.
证人对事件的描述中有一些无法解释的空白。
The plane vanished without a trace, leaving behind an unexplained aviation disaster.
那架飞机消失得无影无踪，留下了一起无法解释的航空灾难。
The patient's recovery from the terminal illness was considered unexplained and miraculous.
患者从绝症中恢复被认为是无法解释的奇迹。
The sudden increase in the company's profits was an unexplained phenomenon.
公司利润的突然增加是一个无法解释的现象。
The unexplained noises in the attic kept the family awake at night.
屋顶阁楼里传来的无法解释的声音让全家夜不能寐。
The ancient artifact's origin and purpose remain unexplained to this day.
这件古代文物的来源和用途至今仍是个谜。
The astronaut's unexplained behavior during the mission raised eyebrows among scientists.
宇航员在任务期间的无法解释的行为令科学家们感到诧异。