The demonstrations were provoked by the unexplained death of an opposition leader.一位反对派领袖莫名身亡, 引发了示威游行。

Soon after leaving Margate, for some unexplained reason, the train was brought to a standstill.不知什么原因, 火车离开马盖特之后不久便停了下来。

How such extensive damage could have been sustained so quickly remains unexplained.为什么这么快就遭受了如此大的损失仍然不得而知。