trolleite

例句：

1. 1. The ancient city is surrounded by several mounds of earth.
   这个古老的城市周围有几个土堆。
2. 2. The mounded structure was built to protect the village from floods.
   这个土墩式结构是为了保护村庄免受洪水侵袭而建造的。
3. 3.The mounded monument stands as a testament to the history of the region.
   这个土墩形石碑是该地区历史的见证。