They jumped on to the rearmost carriages .

他们跳上最后面的几节车厢。

The lorry ran into the back of the rearmost car in the queue which bumped into the car in front , which then hit the next one , and so on in a chain reaction .

那辆卡车撞到了队伍中最后面一辆汽车的尾部，汽车又冲撞到前面的汽车，前面的汽车又碰撞到了再前面的，这形成了连锁的反应。