sand running-down的意思|示意

Unless you're running up and down sand dunes immersing the entire shoe and ankle in sand, the gaiters will do their job at keeping the shoes sand-free.

只要你不是在沙丘上来回跑并将整只鞋和脚踝踩入沙中，鞋罩就能有效地防止沙子进入鞋内。

When I finally came out and sat down, Carson took out a huge hourglass and put it down next to me so that the whole world could see the sand running down.

等我终于出场坐定之后，卡森取出一个巨大的沙漏，放在我的旁边，所有的人都看得见沙子下漏的情况。