inexplicable

For some inexplicable reason, the computer keeps restarting every ten minutes.

(Chinese) 由于某些莫名其妙的原因，这台电脑每隔十分钟就自动重启。

The disappearance of the plane remains inexplicable despite years of investigation.

(Chinese) 尽管经过多年的调查，这架飞机的失踪仍然无法解释。