每日口說挑戰 【科學知識】你知道為什麼秋天葉子會變色嗎? Why Do Autumn Leaves Change Color? (Why Do Autumn Leaves Change Color? - Instant Egghead #51)

今日挑戰句子

Chlorophyll breaks down and is replenished all summer long. As daylight hours shorten, however, veins that bring water and nutrients to the leaf gradually close off.

整個夏天，葉綠素不斷分解，然後又被補足。但是當日照時數縮短的時候，為葉子帶來水分跟營養的葉脈會逐漸關閉。