It is thought that the train hit a boulder that had fallen down a cliff on to the track.

人们认为这列火车撞到了从悬崖滚到铁轨上的大圆石。

《柯林斯英汉双解大词典》

Then they saw their most did not believe the scene, killed by train in the living boulder.

然后他们，看见了他们最不敢相信的一幕，一条龙活生生撞死在巨石。

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A train lays down the embankment with the locomotive underwater in the Douro River, after it rammed into a boulder which derailed the train Monday Dec. 11, 2000 in Baiao, northern Portugal.

一列火车周一在葡萄牙北部的拜尔撞上一颗造成火车出轨的大石后瘫痪在河滨上，火车头则栽进斗罗河里。

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