十万个为什么·科学阅读30篇（9）

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雪花如何形成独一无二的六臂图案且无两片相同

Every snowflake begins as a tiny dust particle floating high in cold, moist air.
Water vapor freezes around it into a hexagonal crystal lattice due to hydrogen bonding.
As the flake falls, temperature and humidity change constantly, adding new branches or smoothing edges.
Tiny differences in air pressure and moisture make each growth path slightly different.
That’s why no two snowflakes follow identical paths through the atmosphere.
Even under lab conditions, scientists can’t reproduce the exact same shape twice.
Microscopes show how arms grow simultaneously but never identically due to random fluctuations.
The six-fold symmetry comes from molecular structure — not from outside forces or design.
Some flakes stay simple plates; others become complex dendrites depending on conditions.
Though rare, identical twins have been found — but only when formed side-by-side in calm air.

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

That’s why no two snowflakes follow identical paths through the atmosphere. 因此，没有任何两片雪花会沿完全相同的路径穿过大气。
Even under lab conditions, scientists can’t reproduce the exact same shape twice. 即便在实验室条件下，科学家也无法两次复现完全相同的形状。
Some flakes stay simple plates; others become complex dendrites depending on conditions. 有些雪花保持简单的片状结构，有些则在特定条件下发育成复杂的枝状晶体。

这篇中文题目最接近哪一句？雪花如何形成独一无二的六臂图案且无两片相同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？每片雪花最初都是一粒悬浮在寒冷潮湿高空中的微小尘埃。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） How Snowflakes Form Unique Six-Armed Patterns Without Any Two Being Alike How to cook noodles A maths worksheet

That’s why no two snowflakes follow identical paths through the atmosphere.

That’s why no two snowflakes follow identical paths through the atmosphere.

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：That’s why no two snowflakes follow identical paths through the atmosphere.