坚硬如岩石的

例句：

1. 1. The sky was ashen with the approach of night.
   随着夜幕的临近，天空变得灰暗。
2. 2. His face was ashen with fear.
   他的脸色因恐惧而苍白。
3. 3. The old tree had been felled and its bark was now ashen.
   那棵老树已被砍倒，现在它的树皮是灰白色的。