I fell on the gravel, severely grazing my knee.我摔倒在砾石路上,膝盖擦伤得很厉害。After driving for so long on the gravel I was glad to get on an even stretch of road.在砾石路上驾驶了那么长时间之后,我很高兴来到了一段平坦的路上。Two young men were racing motorcycles on the loose gravel.两个小伙子正在松散的砾石路面上赛摩托车。