The existence of lacustrine tufa and root-shaped nodule in Badain Jaran Desert proves that the sand dunes and lakes were formed 30 ka ago, and have remained basically unchanged.

巴丹吉林沙漠湖泊中的钙华和根状结核的存在证实这些沙丘和湖泊形成的时间约3万年，而且基本上没有发生大的改变。

youdao

Vicia sativa root nodule is usually rod-shaped, it is mainly composed of many cortex cells and a very large central zone which contains meristem, infected tissue and senescent tissue.

箭舌豌豆根瘤为杆形，主要由皮层细胞和一个体积很大，含有分生组织、侵染组织，有时还有衰老组织的中心区域所组成。

youdao