mysterious ·adjective
Definition: strange or unknown, and not explained or understood Level: B2
一个神秘的陌生人出现在村子边缘，引起了居民们的好奇。
A ___mysterious stranger appeared at the edge of the village, sparking curiosity among the residents.
这件古代文物的神秘失踪仍然是最大的悬案之一。
The ___mysterious disappearance of the ancient artifact remains one of the greatest unsolved cases.
她收到了一个没有寄件人姓名的神秘包裹，这让她既兴奋又不安。
She received a ___mysterious package with no sender's name, which made her both excited and anxious.