【閱讀理解】

For those who study the development of intelligence (智力) in the animal world，self­awareness is an important measurement. An animal that is aware (意識) 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.”

文章通過實驗說明能意識到自身形象的動物具有高智商。

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。細(xì)節(jié)理解題。由文章第二段第一句話“Awareness can be tested by...”可知B項正確。

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。推理判斷題。由第二段最后一句可知人們已經(jīng)知道apes和dolphins是聰明的。

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。推理判斷題。由倒數(shù)第二段可推出Happy能辨別出自己在鏡子中的形象。

(2015·山東省威海市二模)

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(活性免疫系統(tǒng)), but it also plays a role in depression.

“Our original research assumption was that trained muscle would produce a substance(物質(zhì)) 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：體育鍛煉有益身心健康，但是我們的大腦在鍛煉過程中發(fā)生了什么變化從而有益于我們的身心的呢?本文給出了答案：鍛煉的肌肉中產(chǎn)生了一種enzyme物質(zhì)，它帶走了我們身體里的有害物質(zhì)。

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　細(xì)節(jié)理解題。由第四段最后一句話“...but it also plays a role in depression.”可知，Kynurenine會造成我們心情萎靡不振。該題易誤選B項，由第二段倒數(shù)第二句話“molecules that, if out of balance, can stress us and contribute to depression(萎靡不振)”可知，該物質(zhì)本身無害，只有當(dāng)它在身體內(nèi)失衡時才有害，所以不選。

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　細(xì)節(jié)理解題。由第五段最后一句話“...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　推理判斷題。該研究是在老鼠身上做的，但是它與其他研究非常吻合，所以該研究結(jié)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　主旨大意題。由文章大意可知。