冰雪
Ice & Snow
了解水可以是固态（冰和雪）或液态；雪由细小的冻结冰晶组成；冰山是漂浮在海洋中的巨大冰块，大部分体积藏在水面以下；冰会浮起来，因为它比液态水轻。
Know that water can be solid (ice and snow) or liquid, that snow is made of tiny frozen ice crystals, that icebergs are huge chunks of ice floating in the ocean with most of their bulk hidden underwater, and that ice floats because it is lighter than liquid water
学习证据 / Evidence
- 说明冰和雪是冻结的水（固态），水可以在固态和液态之间变化。
- 将冰山描述为漂浮在海洋中的巨大冰块，大部分冰隐藏在水面以下。
- 说明冰会浮起来，是因为冻结的水比液态水轻。
- Explain that ice and snow are frozen water (solid) and that water can change between solid and liquid
- Describe an iceberg as a huge piece of ice floating in the ocean with most of it hidden below the surface
- State that ice floats because frozen water is lighter than liquid water
评估问题 / Assessment
{{name}}知道冰山就像漂浮在海洋上的巨大冰块，大部分冰都藏在水面以下吗？还知道极地地区被冰雪覆盖，是因为那里太冷，水一直保持冻结吗？
Does {{name}} know that icebergs are like floating ice mountains with most of the ice hidden under the water — and that the polar regions are covered in ice because it's so cold the water stays frozen?