mould veining

例句：

1. 1. The old house has a lot of mould veining on its walls.
   这所老房子的墙壁上有很多霉菌纹。
2. 2. The mold veining on the surface of the soil is a sign of poor drainage.
   土壤表面的霉菌纹是排水不良的迹象。
3. 3. The mold veining in the paint was due to an improper ventilation system.
   油漆中的霉菌纹是由于通风系统不当造成的。