十万个为什么·科学阅读30篇（2）

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为什么某些蛤蜊受惊时会发光，但仅限于夜间？

These clams contain symbiotic bacteria that emit blue-green light through bioluminescent chemical reactions.
Light production occurs only in darkness because daylight suppresses the enzyme luciferase activity.
The flash startles predators, giving the clam time to bury itself deeper in sand quickly.
Nocturnal behavior aligns with peak predator activity, maximizing survival advantage.
Researchers discovered that melatonin levels in clam tissues regulate light sensitivity rhythmically.
Unlike fireflies, clams cannot control flashes voluntarily—they respond purely to mechanical shock.
Oceanographers use this trait to monitor coastal health and plankton bloom timing.
The light wavelength matches deep-water transmission peaks, enhancing visibility underwater.
Genetic studies show light-emission genes activate only under low-light transcription factors.
This circadian-linked defense reveals how marine life times responses to environmental cycles.

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

Nocturnal behavior aligns with peak predator activity, maximizing survival advantage. 夜行习性与捕食者活跃高峰同步，最大化生存优势。
The light wavelength matches deep-water transmission peaks, enhancing visibility underwater. 发光波长匹配深水透光峰值，增强水下可见度。
Genetic studies show light-emission genes activate only under low-light transcription factors. 基因研究表明，发光基因仅在低光转录因子作用下才被激活。

这篇中文题目最接近哪一句？为什么某些蛤蜊受惊时会发光，但仅限于夜间？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？这些蛤蜊体内含有共生细菌，能通过生物发光化学反应发出蓝绿色光。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 Certain Clams Produce Light When Disturbed — But Only at Night? How to cook noodles A maths worksheet

Nocturnal behavior aligns with peak predator activity, maximizing survival advantage.

Nocturnal behavior aligns with peak predator activity, maximizing survival advantage.

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：Nocturnal behavior aligns with peak predator activity, maximizing survival advantage.