【阅读理解】
For those who study the development of intelligence (智力) in the animal world，selfawareness is an important measurement. An animal that is aware (意识) of itself has a high level of intelligence.
Awareness can be tested by studying whether the animal recognizes itself in the mirror, that is, its own reflected image (反射出的影像). Many animals fail this exercise bitterly, paying very little attention to the reflected image. Only humans，and some intelligent animals like apes and dolphins，have been shown to recognize that the image in the mirror is of themselves.
Now another animal has joined the club. In the Proceedings of the National Academy of Sciences, researchers report that an Asian elephant has passed the mirror selfreflection test.
“We thought that elephants were the next important animal，”said Diana Reiss of the Wildlife Conservation Society, an author of the study with Joshua M. Plotnik and Fans B. M. de Waal of Emory University. With their large brains，Reiss said, elephants “seemed like cousins to apes and dolphins.”
The researchers tested Happy. Maxine and Patty, three elephants at the Bronx Zoo. They put an 8footsquare mirror on a wall of the animals' play area (out of the sight of zoo visitors) and recorded what happened with cameras, including one built in the mirror.
The elephants used their long noses to find what was behind it，and to examine parts of their bodies.
Of the three, Happy then passed the test，in which a clear mark was painted on one side of her face. She could tell the mark was there by looking in the mirror, and she used the mirror to touch the mark with her long nose.
Diana Reiss said，“We knew elephants were intelligent, but now we can talk about their intelligence in a better way.”
文章通过实验说明能意识到自身形象的动物具有高智商。
1. What can mirror tests tell us about animals?
A. Whether they have large brains. B. Whether they have selfawareness.
C. Whether they enjoy outdoor exercises. D. Whether they enjoy playing with mirrors.
答案：B。细节理解题。由文章第二段第一句话“Awareness can be tested by...”可知B项正确。
2. Why does the author mention apes and dolphins in the text?
A. They are most familiar to readers.
B. They are big favorites with zoo visitors.
C. They are included in the study by Reiss.
D. They are already known to be intelligent.
答案：D。推理判断题。由第二段最后一句可知人们已经知道apes和dolphins是聪明的。
3. What made Happy different from Maxine and Patty?
A. She used her nose to search behind the mirror.
B. She recognized her own image in the mirror.
C. She painted a mark on her own face.
D. She found the hidden camera.
答案：B。推理判断题。由倒数第二段可推出Happy能辨别出自己在镜子中的形象。
(2015·山东省威海市二模)
Run, swim, lift weights, do yoga—do something, because it's good for you. Many studies tell us that regular exercise not only helps our bodies but improves memory, and eases anxiety. But what is happening to the mind during workout to create all these benefits?
A new study from Sweden suggests that a specific protein found in trained muscles might contribute to exercise's mental benefits. This protein, the researchers found, might help our bodies process molecules that, if out of balance, can stress us and contribute to depression(萎靡不振). The findings were published in the journal Cell.
To test this, the researchers kept attacking some mice with flashing lights, loud noises and interrupting their sleep for weeks. Predictably, this treatment makes the mice show signs and biochemical markers of depression.
But not all the mice showed those signs. One group, specially raised to have high levels of a protein called PGC1alpha1 (the one in trained muscles), did not show those depression signs. PGC1alpha1 increases production of an enzyme that breaks down a chemical called kynurenine. Kynurenine helps the body respond to an activated immune system(活性免疫系统), but it also plays a role in depression.
“Our original research assumption was that trained muscle would produce a substance(物质) with beneficial effects on the brain，” Jorge Ruas of the Karolinska Institute told Forbes.com. “We actually found the opposite: welltrained muscle produces an enzyme that removes harmful substances away from the body.”
This study was in mice, but it lines up nicely with all the other lines of evidence that exercise is good for mental health.
文章大意：体育锻炼有益身心健康，但是我们的大脑在锻炼过程中发生了什么变化从而有益于我们的身心的呢?本文给出了答案：锻炼的肌肉中产生了一种enzyme物质，它带走了我们身体里的有害物质。
12.According to the study, which of the following is bad for your mental health?
A.Protein. B.Molecule.
C.Enzyme. D.Kynurenine.
答案：D 细节理解题。由第四段最后一句话“...but it also plays a role in depression.”可知，Kynurenine会造成我们心情萎靡不振。该题易误选B项，由第二段倒数第二句话“molecules that, if out of balance, can stress us and contribute to depression(萎靡不振)”可知，该物质本身无害，只有当它在身体内失衡时才有害，所以不选。
13.What conclusion have the researchers drawn from the study?
A.Unbalanced exercise leads you to depression.
B.Wellfed mice survive better though being illtreated.
C.Trained muscle produces a substance good for brain.
D.Regular exercise helps to clear rubbish away from body.
答案：D 细节理解题。由第五段最后一句话“...welltrained muscle produces an enzyme that removes harmful substances away from the body...”可知。
14.According to the last paragraph, the result of the study is ________.
A.reliable B.doubtful
C.predictable D.ambiguous
答案：A 推理判断题。该研究是在老鼠身上做的，但是它与其他研究非常吻合，所以该研究结果是可信的。
15.What's the main idea of the passage?
A.Why do you need regular exercise?
B.What matters most for your body?
C.How does exercise help your brain?
D.Why are mice chosen for the study?
答案：C 主旨大意题。由文章大意可知。
