宝春

各位同学们，为了督促帮助大家持续提升英语能力，培君老师们特意给大家准备了托福每日一包。每天覆盖听说读写内容，坚持完成两周以上，就能见到自己的英语能力不断上涨哟。

1. 听写包 答案：

According to the classic theory, this is true for the red pigment as well.

It was there in the leaf all along but it was hidden by the green chlorophyll.
OK, so that’s the classic explanation and it’s partially right. Why do I say partially?
Well, it’s probably true for pigments like yellow or orange, but it doesn’t seem to hold for the red pigment.
Let’s back up a bit. Just what produces this red color in leaves? It’s a red pigment called anthocyanin.
Here is where the classic explanation doesn’t seem to apply to red.
What’s interesting is that during the summer there was very little if any anthocyanin in the leaves,
but in the weeks before a tree is about to drop its leaves, the production of anthocyanins increases significantly.
In other words, unlike those other pigments, anthocyanins are not just unmasked by the breakdown of chlorophyll in autumn;
they are actually created at this time.
So that raises a question, why would a tree produce more anthocyanin just before dropping its leaves?
Why does the tree spend so much of its resources doing this just before the leaves fall off?
On the surface, that doesn’t make sense.
根据传统理论，这对红色也适用。
它一直存在于树叶中，但是被绿色的叶绿素藏起来了。
好了，这是传统的解释，部分是对的。为什么我说部分？
因为这对像黄色和橘色这样的色素可能是正确的，但是似乎不适用于红色色素。
我们往回倒一点。什么产生了树叶中的红色呢？是一种叫做花青素的红色色素。
这就是传统解释似乎不适用于红色的地方。
有趣的是在夏天，树叶中几乎没有花青素，
但是一棵树开始落叶前几个周，花青素开始大量增加。
换句话说，和其他的色素不同，花青素不是因为叶绿素在秋天分解而开始显现，
它们实际上是那个时候才产生的。
那么这就提出了一个问题：一棵树在落叶之前为什么要制造出更多的花青素？
为什么树要在所有的树叶掉落之前花那么多资源这么做？
从表面来看这一点都说不通。

2.阅读包答案：

同其他地方一样，欧洲的多媒体集团越来越成功，这些集团将相关的电视、广播、报纸、杂志及出版社等媒体联合在一起。

3.写作包答案：

The world-renowned Silk Road is a series of routes connecting the East and the West. It extended more than 6,000 kilometers. The Silk Road was named after ancient China’s silk trade which played an important role in the civilization development of China, South Asia, Europe and the Middle East. It was through the Silk Road that papermaking, gunpowder, compass and printing of the four great inventions of ancient China were introduced around the world. Similarly, Chinese silk, tea and porcelain spread all over the world. Europe also exported various goods and plants through the Silk Road to meet the needs of the Chinese market.