grey mull

例句：

1. 1. The grey mull was so thick that it made walking difficult.
   灰色的泥泞太厚了，以至于走路都很困难。
2. 2. The farmer had to dig his way through the grey mull to reach his crops.
   农民不得不穿过灰色的泥泞去到达他的庄稼。
3. 3. The grey mull was a sign of bad weather approaching.
   灰色的泥泞预示着恶劣天气的来临。