Read the article and select the best answer. Article: Burning less calories while walking seems like a bad idea, but making the walk easier may actually keep people on their feet longer, and that scientists say, has substantial health benefits. Analyzing the human walk, biomedical engineers Steven Collins and Greg Sawicki concluded that our ankles and calves perform motions similar to a spring coupled with a clutch that intermittently stores and releases energy. Sawicki, from the University of North Carolina, explained what's involved. "We found in basic science experiments that that system, your calf and Achilles tendon, works a lot like a catapult. So, the muscle holds on to the tendon and your body actually stretches your Achilles tendon quite a bit and then stores the energy in the tissue and then it's given back to _ you forward in the world," he said. Sawicki said he and his colleague Steven Collins at Carnegie Mellon University designed a mechanical device, made of carbon fiber and metal, that performs the same sequence of energy give-and-take outside the body. The system takes over part of the work of walking, and reduces the amount of required energy by as much as seven percent. Wearing the unpowered ankle exoskeleton can help people either walk farther with the same amount of energy, or restore the normal movement pattern for people who have trouble walking. Sawicki said it takes only a few minutes to get used to the exoskeleton but the wearer quickly learns to tone down the muscle energy as the device takes over part of the load. "You really don't notice it until when you take it off. And when you take it off you realize that it was there and giving you the boost," he said. Sawicki added that the device is primarily intended for people recovering from surgery or a stroke. But all persons who spend a lot of time walking, such as police officers or hospital personnel, could benefit from it. At the moment there are no plans to develop the ankle exoskeleton for the market, but the inventors say some manufacturers have expressed interest. Question: What's the main idea of the passage? Options: A: How to reduce energy whiling walking. B: Ways to make walking easy. C: Introduction to a mechanical device to make walk easier D: Guidelines for people recovering from surgery.
C

(Question)
Read the article and select the best answer. Article: The so-called post-90s generation have become even much "cooler" than the 1980s group, for they can speak "Martian language", a difficult code-like language created by themselves. And they probably think it very original and smart. The idea of this language is to prevent the authorities- parents and teachers- from understanding what is said. Ms. Li, mother of a 15-year-old girl, logged onto her daughter's online space and found lines of codes, mixed English, Japanese and half-finished Chinese characters, which looked completely meaningless to her. Her daughter told her that it was "Martian language" and her _ all used it. The new language is becoming very popular in online spaces- so much so that even some translating software has been created to translate the normal language into "Martian language". A 14-year-old netizen, nicknamed "S. _ Tangguo", explained that the language could be created by anyone. "At first, I just copied the language form other people's articles. Later , I began to create some words by myself. I split some Chinese characters, or use words that have similar pronunciations to interchange with each other, or even add some English, Japanese or Korean words into my article, and that makes the new language. My classmates all chat in 'Martian language'. It's in style and can help us hide our secrets from our parents or teachers." Unlike the worried parents, some experts have found positive aspects in the spread of this unusual online language. Wang Haiyong, a psychologist ,said that there's no need to be too worried about the phenomenon. This so-called "Martian language" is just a little hobby of the post-90s generation. On the other hand, the new language can inspire children's imaginations, which is a good thing. However, Wang also advised teachers and parents to give proper guidance to their children, helping them better distinguish between online language and the normative language of real life. Question: What is the correct attitude we should take towards "Martian language" according to the psychologist? Options: A: Parents should worry about losing control over their children. B: All generations should learn to be cooler by using the new language. C: We should help children understand the difference between the hobby online and the standard language. D: The authorities themselves should try to use the new language.
(Answer)
C

Read the article and select the best answer. Article: I became a stand- up comic at 12:45 yesterday afternoon when I walked onto a comedy club stage and did a "bit". It was an audition in which people had exactly two minutes each to perform for a producer. I am not a comic, have never appeared onstage, am awkward before many people, and have no social skills. But I have written some funny things in the newspapers, and I figured that if you can write funny, you can be funny. That was my first mistake. Good stand - up comics improve their acts over months if not years, practicing before bathroom mirrors or their friends. I developed the key skill the morning I went on. I also brought a box of plastic beads , because I figured they could be useful. For the first few seconds, I was simply staring forward, mouth open, expressing the concept:"Uuungh". Finally I said, "This is my first performance as a stand - up comic. It's a kind of a special moment for me. I'd like to take this opportunity to say something to my mother, who was an inspiration to me throughout my life. My mother passed away a few years ago, but I feel she is still with me. All the time, wherever I go, I feel her presence. Day in and day out. So I would like to say this to her. LEAVE ME ALONE, MA!" Some people actually laughed. Then I said, "Anyway, this really is my first time onstage, and I'm pretty nervous because I'm not all that funny and I have a really bad stage presence. But I've been working on the problem. A long time ago a Greek guy named Demosthenes had the same problem I have, and he became a great speaker by sticking pebbles in his mouth, so I thought I would (and here I began putting the beads in my mouth) try that. See, the idea is that if you can talk through the pebbles ( now I was putting them in by the handful) you can learn to talk better and wfnm fmuff frmphm grphnm . . ." More laughter. I looked at my watch, said something that might have sounded like "My time is up," and left to somewhat spirited applause. What the audience did not know was that I was quietly choking... Question: We can learn from the text that the author _ . Options: A: is a professional comic B: has rich stage experience C: is good at communicating with others D: has had his stories published in the newspapers
D