crustae

例句：

1. 1. The farmer had to wait until the frost lifted before he could plant his crops.
   农民不得不等到霜融化后才能种植他的庄稼。
2. 2. The cold weather caused the ground to freeze, making it difficult for animals to move around.
   寒冷的天气使地面结冰，使得动物难以移动。
3. 3.The farmers were worried about the risk of frost damage to their crops.
   农民们担心霜冻对作物可能造成的风险。