科学素养与生活应用·英语30篇（4）

18 / 30

已读 0 / 30 课

秋叶变色之谜：超越温度的化学机制

Leaf color change begins when shorter days trigger hormonal shifts inside tree tissues.
Chlorophyll breaks down slowly, revealing pre-existing yellow and orange carotenoid pigments.
Red anthocyanins form anew in fall as sugars get trapped in leaves under sunny, cool conditions.
Soil moisture and nutrient levels also influence pigment intensity and timing each year.
Maple trees produce vivid reds because they actively synthesize anthocyanins before leaf drop.
Scientists analyze leaf samples with spectrophotometers to quantify pigment ratios precisely.
Climate change is altering typical color onset dates and duration across temperate forests.
Some trees retain green leaves longer due to genetic traits affecting abscission layer formation.
Photographers and ecologists alike use leaf-color maps to track seasonal ecosystem responses.
Understanding this chemistry helps predict forest health and carbon cycle feedbacks.

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

Chlorophyll breaks down slowly, revealing pre-existing yellow and orange carotenoid pigments. 叶绿素缓慢分解，显露出原本就存在的黄色和橙色类胡萝卜素色素。
Scientists analyze leaf samples with spectrophotometers to quantify pigment ratios precisely. 科学家用分光光度计分析叶片样本，精确测定各类色素的比例。
Understanding this chemistry helps predict forest health and carbon cycle feedbacks. 理解这一化学过程有助于预测森林健康状况及碳循环反馈效应。

这篇中文题目最接近哪一句？秋叶变色之谜：超越温度的化学机制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？日照变短会触发树木组织内的激素变化，从而开始叶片变色。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 Autumn Leaves Change Color: Chemistry Beyond Temperature How to cook noodles A maths worksheet

Chlorophyll breaks down slowly, revealing pre-existing yellow and orange carotenoid pigments.

Chlorophyll breaks down slowly, revealing pre-existing yellow and orange carotenoid pigments.

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：Chlorophyll breaks down slowly, revealing pre-existing yellow and orange carotenoid pigments.