科学为什么·英语30篇（1）

3 / 30

已读 0 / 30 课

为什么冰能浮在水面上？

Unlike most solids, ice floats because frozen water is less dense than liquid water—a rare and vital exception.
When water cools below 4°C, hydrogen bonds begin locking molecules into an open hexagonal lattice.
This crystal structure creates empty spaces between molecules, increasing volume while decreasing density.
At 0°C, ice is about 9% less dense than liquid water, giving it natural buoyancy.
If ice sank, lakes and oceans would freeze solid from the bottom up, killing most aquatic life.
Instead, floating ice insulates the water below, allowing fish and microbes to survive winter beneath the surface.
This density anomaly also drives ocean circulation, as cold, dense water sinks near poles and flows toward the equator.
Scientists call this behavior ‘density inversion,’ and it’s one reason Earth supports complex life.

听 → 读 → 学表达 → 懂 → 今天会说这一句 → 跟读录音 → 自己说一句。

This crystal structure creates empty spaces between molecules, increasing volume while decreasing density. 这种晶体结构使分子间出现空隙，体积增大而密度降低。
Scientists call this behavior ‘density inversion,’ and it’s one reason Earth supports complex life. 科学家称此现象为‘密度反转’，它也是地球能孕育复杂生命的原因之一。
When water cools below 4°C, hydrogen bonds begin locking molecules into an open hexagonal lattice. 当水温降至4°C以下时，氢键开始将水分子锁定成疏松的六方晶格。

这篇中文题目最接近哪一句？为什么冰能浮在水面上？一次学校运动会的通知一份超市购物清单

课文第一句的意思更接近？与大多数固体不同，冰能漂浮，因为固态水的密度小于液态水——这是一种罕见却至关重要的例外。今天学校放假了。请把窗户打开。

这一课主要在讲什么？（看英文标题） Why Does Ice Float on Water? How to cook noodles A maths worksheet

This crystal structure creates empty spaces between molecules, increasing volume while decreasing density.

This crystal structure creates empty spaces between molecules, increasing volume while decreasing density.

第一版：录下来、回听、再听标准音。系统打分以后再加。

用今天的表达，自己说一句。

例子：This crystal structure creates empty spaces between molecules, increasing volume while decreasing density.