a compact mass of sand

• 坚实的沙堆

a compact mass of sand的用法和样例：

例句

1. When I was in Africa, I had to cross so many huge banks of sand.
   在非洲时，我总得穿过很多巨大的沙堆。
2. To see it better, Carson climbed on to the mound of sand he had excavated and stood there staring.
   卡森爬上刚才挖出的沙土所堆成的沙堆，那样可以看得更清楚些。