十万个为什么·科学启蒙30篇（1）

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为什么有些云会下雨，而另一些不会？

Rain forms only when cloud droplets grow heavy enough to fall past rising air currents.
Tiny water droplets usually stay suspended unless they collide and merge repeatedly.
In cold clouds, ice crystals form and attract vapor, growing faster than droplets.
Wind patterns, humidity, and temperature layers all affect whether droplets grow big enough.
Cumulonimbus clouds are tall and turbulent, giving droplets time and space to grow.
Stratus clouds are thin and stable, so droplets rarely reach raindrop size.
Dust, salt, or pollen particles act as nuclei around which water condenses.
Without enough nuclei, clouds may hold moisture but never release rain.
Meteorologists use radar to track droplet size and predict rainfall chances.
That’s why fog looks like a cloud on the ground—but rarely rains.

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

Without enough nuclei, clouds may hold moisture but never release rain. 若凝结核不足，云中虽含水分，却难以形成降雨。
Meteorologists use radar to track droplet size and predict rainfall chances. 气象学家利用雷达监测水滴大小，预测降雨概率。
Tiny water droplets usually stay suspended unless they collide and merge repeatedly. 微小水滴通常悬浮在空中，除非反复碰撞并合并。

这篇中文题目最接近哪一句？为什么有些云会下雨，而另一些不会？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？只有当云中水滴变得足够重，能穿过上升气流下落时，才会形成降雨。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 Do Some Clouds Produce Rain While Others Don’t? How to cook noodles A maths worksheet

Without enough nuclei, clouds may hold moisture but never release rain.

Without enough nuclei, clouds may hold moisture but never release rain.

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：Without enough nuclei, clouds may hold moisture but never release rain.