lisen to the CD:3a,汉语三
play games:round and round、螃蟹歌
field trip:爬山踩树叶,观察树和叶儿,农家乐。重阳节登高赏叶主题。坡峰岭实在是选错地方了,人山人海,另外没法滚树叶,也就踩踩,采采,看看。
Why do leaves change color in the autumn?
Most of the spectacular colors of autumn have actually been in the leaves all Summer,秋天最壮观的色彩实际上是整个夏天的树叶。
however they were ‘covered up’ by the dominant green of the chlorophyl.
然而他们“掩盖”的是叶绿素主导的绿色。
As weather cools,and shorter days settle in,the chlorophyl begins to break down,revealing new and varied color pigments.
随着天气变冷,短日处理,叶绿素开始分解,揭示新的、不同颜色的颜料。
The brightest colors are seen when late summer is dry,and autumn has bright sunny days and cool nights.
最亮的颜色在夏末干燥时出现,秋天有明亮的晴天和凉爽的夜晚。
xanthophyll叶黄素Aspen杨树
carotene胡萝卜素sugar maple 枫树
anthocyanin花青素swamp chestnut oak 沼生栎
chlorophyl叶绿素white birch白桦
叶子结构:叶片、叶柄、叶脉。
blade(lamina)、petiole、leaf vein .