freezing nuclei

例句：

1. 1. The ice crystals are starting to form on the surface of the lake.
   湖面上开始形成冰晶。
2. 2. The scientists found that the freezing nuclei were responsible for the formation of the ice layer.
   科学家们发现，冻结核是形成冰层的原因。
3. 3. The freeze-thaw cycle is essential for the growth and survival of many organisms.
   冻融循环对许多生物的生长和生存至关重要。