freezing and thawing

例句：

1. 1. The lake freezes over during the winter months.
   冬天的时候，湖面结冰。
2. 2. Thawing the frozen ground is essential for planting new crops.
   解冻冻土是种植新作物所必需的。
3. 3. During the summer, the ice on the lake begins to thaw.
   夏天的时候，湖面上的冰开始融化。