noun [具体名词]（受水或天气侵蚀而成的）巨石，巨砾
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。
- boulder 出现在下面的课文中
- Lesson 39 Nothing to worry about boulder 名词: 大石块
单词造句:
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。