十万个为什么·科学阅读30篇（9）

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为什么有些云会下雨，而另一些云却始终干燥？

Clouds form when warm, moist air rises and cools enough for water vapor to condense into tiny droplets.
These droplets must grow large and heavy enough to overcome updrafts before they can fall as rain.
In cumulonimbus clouds, strong vertical winds help droplets collide and merge rapidly into raindrops.
But in thin cirrus clouds, ice crystals are too small and widely spaced to combine effectively.
Some clouds lack sufficient moisture or updraft strength, so droplets never reach falling size.
Temperature differences between cloud layers also affect whether droplets freeze or remain liquid.
Scientists use radar and satellite data to track droplet growth and predict rainfall likelihood.
Even when clouds look thick, they may contain too few nuclei for efficient rain formation.
This explains why deserts often have dramatic clouds that never release a single drop.
Rain production depends on a precise balance of humidity, temperature, and air motion.

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

Temperature differences between cloud layers also affect whether droplets freeze or remain liquid. 云层间的温度差异也会影响水滴是冻结还是保持液态。
Rain production depends on a precise balance of humidity, temperature, and air motion. 降雨产生依赖湿度、温度与空气运动之间的精确平衡。
In cumulonimbus clouds, strong vertical winds help droplets collide and merge rapidly into raindrops. 在积雨云中，强烈的垂直气流促使水滴快速碰撞合并成雨滴。

这篇中文题目最接近哪一句？为什么有些云会下雨，而另一些云却始终干燥？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？云由暖湿空气上升并冷却至水蒸气凝结成微小水滴而形成。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 Some Clouds Produce Rain While Others Stay Dry How to cook noodles A maths worksheet

Temperature differences between cloud layers also affect whether droplets freeze or remain liquid.

Temperature differences between cloud layers also affect whether droplets freeze or remain liquid.

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：Temperature differences between cloud layers also affect whether droplets freeze or remain liquid.