In the yard she saw a girl and boy playing in their sand pile.

提比看到院子里一个男孩和女孩正在沙堆上玩耍。

As sand piles and avalanches, the whole dune may even move or migrate, over months or years.

随着沙堆和崩塌，整个沙丘甚至可能在几个月或几年内移动或迁移。

" Oh, look! look! " cried the girl, jumping up from the sand pile and running toward the house as fast as she could.

“啊，快看！快看！”女孩一边叫着，一边从沙堆上跳了起来，飞快地跑向屋子。