初三英语听力：鸟类并不笨头笨脑
Neuroscientists' opinions about the brains of birdshave changed.
神经系统科学家关于鸟类大脑的传统观念发生了转变。
In humans and other mammals,the roof of theforebrain has evolved into the cerebral cortex, astructure responsible for flexiblelearning andreasoning.
人类和其他哺乳动物的前脑顶层已经进化为大脑皮层，这一结构主管弹性学习和推理能力。
Early neuroanatomists thought that the forebrainroof was small and simple in birds, with itsforebraininstead being dominated by structures in its base, called the basal ganglia.
早期的神经系统科学家认为鸟类的前脑顶层在大脑中面积小，构造简单，且并非由大脑基底部名为基底神经节的结构组成。
Without anelaborate forebrain roof, it seemed that birds couldn't be very smart.
因此，鸟类并不拥有复杂精妙的前脑顶层，这似乎决定了鸟类智商有限。
Recent research shows that birds are a lot smarter than scientists once thought.
最近的研究表明鸟类要比科学家想象的聪明得多。
To give just afew examples, the New Caledonian crow can manufacture and use tools.
例如，新喀里多尼亚乌鸦会制作和使用工具。
The African grey parrotcan learn to classify objects into categories, and the Florida scrub jaystores food in dozens ofcaches and can remember their locations for future use.
非洲灰鹦鹉能学会对东西进行分类，佛罗里达灌丛鸦会将食物存储在不同的地方，并且能记住位置，以备将来之需。
It turns out that neuroanatomists had it all wrong about bird forebrains.
结果是神经解剖学家 对鸟类前脑的研究完全错误。
During more than 300 million years of separate evolution, the forebrain roofs of birds and ofmammals each grew largerand more elaborate, but in different ways.
初三英语听力：Airplanes-飞机
Airplanes are amazing. How does something so big and heavy get off the ground? I’m alwaysamazed at how the millions of different parts work together. Travelling by airplane is always a wonderful experience. I don’t care whether economy class is cramped and has no space. I like playing with the in-flight entertainment system, especially now they have all the latest movies. I also love airplane food. Many of my friends say it’s disgusting, but I love it. I often ask the passenger next to me if I can have the dessert or roll they don’t want. The only thing I don’t like about planes is turbulence. When the airplane hits those air pockets, I always worry we’ll crash. But I once read that turbulence has never caused an airplane to crash.
初三英语听力：脂肪储存的来龙去脉
When you eat a fatty food, it moves through thestomach andon to the intestines.
当你食用富含高脂肪的食物时，脂肪通过胃流入肠道。
In the intestines, a number of processes occur totransfer fat from the foodto special fat cells in yourbody.
在肠道中，脂肪经过一系列的消化流程从食物转化为体内的特殊脂肪细胞。
First, the gall bladder produces bile that breaks thefood's fat droplets into smaller droplets.
首先，胆囊分泌胆汁分解食物脂肪滴，使其更小。
Next,the pancreas secretes enzymes that attack the fat droplets and break them down into twoparts:fatty acids and glycerol.
然后，胰腺分泌胰腺酶作用于脂肪滴，将其分解为两个部分：脂肪酸和甘油。
This happens because fat droplets are too big to pass through cell membranes.
这是因为脂肪滴过大，无法穿过细胞膜。
The broken downfat is absorbed by the cells lining the intestine, where it is reassembled intofat molecules andeventually shuttled into the bloodstream with the help of lipoproteinparticles.
分解的脂肪被肠粘膜细胞吸收，重组成脂肪细胞，最后负载在脂蛋白颗粒上进入血液循环。
For the most part fat is stored in the fat cells that compose fatty tissue.
大部分的脂肪储存在脂肪细胞内，形成脂肪组织。
Think of a fat cell as a tinyplastic bag filled with a drop of fat.
脂肪细胞好比一个容纳脂肪滴的塑料袋。
Interestingly, fat cells do not multiply.
有趣的是，脂肪细胞并不会变多。
The body contains a finitenumber of fat cells that expand as they absorb fat.