The current was quite strong, and I just stayed behind the boulder.(水流非常强，摄影师只能呆在巨石后面。)
I was about to give up when I saw a pile of small stones jammed under a boulder.(我正打算放弃，忽然看见其中一块圆石下面有一摞石头。)
In Boulder, Colo., a surge of electricity on the power grid can largely go unnoticed.(在科罗拉多州波尔得市，大部分电网的电力波动都不被人们察觉。)
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。)
They then walked hand in hand toward the large boulder that marks the area where Flight 93 crashed.(然后，两人手挽手走向大卵石标记的93号航班坠毁地点。)
Given enough warning, it should be possible to push a threatening boulder out of the way.(如果予以足够的警示，就有可能把一块有威胁性的巨石推开。)
Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity.(一旦你开始滚动巨石，它就产生动量，动量由它的质量和速度决定。)
In ancient times, a king had a boulder placed on a roadway.(古时候，一位国王将一块巨石放在路上。)
Mediterranean: angry to see the glittering sea-pale boulder alive(它恼怒地看着闪烁的海面，巨大的卵石上爬着绿蜥蜴)
As with Sisyphus, the boulder was painstakingly rolled upwards only to tumble back down again in an absurd exercise of futility.(和西西弗斯一样，巨石费力地向上滚动，结果又滚了下来，徒劳无功。)
