C
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 propel 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.What’s the main idea of the passage?
| 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. |
What is true according to the passage ?
| A．The device can only benefit people with walking problems. |
| B．All people could benefit from it. |
| C．With the device, the walkers need seven percent as much as the energy otherwise. |
| D．The device can benefit people in the long term. |
What does the underlined word ” propel” mean in paragraph 3?
| A．put | B．keep | C．help | D．push |
What can we learn from the last paragraph?
| A．The ankle exoskeleton will have a bright future. |
| B．The ankle exoskeleton hasn’t appeal to manufacturers. |
| C．The ankle exoskeleton will be launched in the market soon. |
| D．The ankle exoskeleton will never be produced. |
At the time friends visit us in the evening, they often tell us they are in a hurry and look at their watches. It isn't that our friends are all very busy; it is just that we haven't got a television. People think that we are very strange. “But what do you do in the evening?”，they are always asking. The answer is very simple. Both my wife and I have hobbies. We certainly don't spend our evenings looking at the walls. My wife enjoys cooking and painting and often attends evening classes in foreign languages. This is quite useful as we often go abroad for our holidays. I collect stamps and I'm always busy with my collection. Both of us enjoy listening to the music and playing chess together.
Sometimes there are power（电源） cuts and we have no electricity in the house. This does not worry us and we just light candles and carry on with what we were doing before. Our friends, however, are lost－no television!—So they don't know what to do. On such evenings our house is very full for they all come to us. They all have a good time. Instead of sitting in silence in front of the television, everybody talks and plays games.The couple have not got a television, because ________.
| A．they are not rich enough |
| B．they are strange people |
| C．they enjoy spending evenings in their own ways |
| D．they don't know what to do when there are power cuts |
Both of them are interested in __________.
| A．learning languages |
| B．travelling |
| C．staying home alone |
| D．watching people play games |
At night when there is no electricity, the couple ________.
| A．have to look at the walls |
| B．can do nothing but sit in silence |
| C．will have many visitors |
| D．have to go out for candles |
The writer tries to tell us that ________.
| A．life is possible without a television |
| B．life is enjoyable with many friends |
| C．electricity is important |
| D．television is useful |
The best title for this passage is ________.
| A．Why Do We Need a Television? |
| B．Candle! But No Electricity! |
| C．Different Friends, Different Hobbies. |
| D．We Go Without Televisions ！ |
I first went to Harrow in the summer term. The school had the biggest swimming pool I had ever seen. It was a good joke to come up behind a naked boy, and push him into the pool. I made quite a habit of this with boys of my own size or less.
One day 1 saw a boy wrapped in a towel on the side of the pool. He was no bigger than I was, so I thought him a fair game. Coming secretly behind, I pushed him in, holding on to his towel so that it would not get wet, I was surprised to see an angry face come out from the water, and a being of great strength making its way by fierce strokes(猛力地划)to the shore. I fled, but in vain. He overtook me, seized me violently, and threw me into the deepest part of the pool. I soon climbed out on the other side, and found myself surrounded by a crowd of younger boys. ‘‘Do you know what you have done?" they said，“ It's Amery ；he is in Grade Six. He is champion at gym. He has got his football honor. ”
I was frightened and felt ashamed. How could I tell his position when he was wrapped in a bath towel and so small. He didn't seem pleased at all, so I added in a most brilliant word，“ My father, who is a great man, is also small. ” At this he laughed, and after some general words about my rude behavior and how I had better be careful in the future, signified the incident was closed. The writer thought Amery "a fair game "because the boy ________.
| A．looked like an animal |
| B．was fond of games |
| C．was of similar size |
| D．was good at sports |
The writer felt" ashamed" because ________.
| A．he was laughed at by other boys |
| B．Amery turned out to be in the same grade |
| C．he pushed Amery hard and hurt him |
| D．he played a joke on an outstanding athlete |
By saying “ My father, who is a great man, is also small”，the writer ________.
| A．tried to please Amery |
| B．challenged Amery |
| C．threatened Amery |
| D．admired his father |
Which of the following is TRUE?
| A．The writer could run faster than Amery. |
| B．The writer liked playing on boys of all sizes. |
| C．Amery was a student in Grade Four， |
| D．Amery forgave the writer for his rude behavior. |
What does the underlined word "overtook" mean?
| A．caught hold of |
| B．caught up with |
| C．took a look at |
| D．shouted at |
Pop stars today enjoy what once only belonged to the royalty(皇室）. Wherever they go, people turn out in their thousands to greet them. The crowds go wild trying to catch a brief glimpse of their smiling, colorfully dressed idols. The stars are transported in their chauffeur driven Rolls-Royces, private helicopters or executive aero planes. They are surrounded by a permanent entourage (随从）of managers, press agents and bodyguards. Photographs of them appear regularly in the press and all their comings and goings are reported, for, like royalty, pop stars are news. If they enjoy many of the privileges of royalty, they certainly share many of the inconveniences as well. It is dangerous for them to make unscheduled appearances in public. They must be constantly shielded from the adoring crowds who idolize them. They are no longer private individuals, but public property. The financial rewards they receive for this sacrifice cannot be calculated, for their rates of pay are great.
And why not? Society has always rewarded its top entertainers lavishly. The great days of Hollywood have become legendary ： famous stars enjoyed fame, wealth and adulation (奉承）on an all-time scale. By today's standards, the excesses of Hollywood do not seem quite so spectacular. A single gramophone record nowadays may earn much more in royalties than the films of the past ever did. The competition for the title "Top of the Pops” is fierce, but the rewards are truly huge.
It is only right that the stars should be paid in this way. Don't the top men in industry earn enormous salaries for the service they perform to their companies and their countries? Pop stars earn vast sums in foreign currency—often more than large industrial companies- and the taxman can only be grateful for their massive annual contributions to the exchequer (国库）• So who would begrudge them their rewards?
It's all very well for people in boring jobs to complain about the successes and rewards of others. People who make envious remarks should remember that the most famous stars represent only the tip of the iceberg. For every famous star, there are hundreds of others struggling to earn a living. A man working in a steady job and looking forward to a pension at the end of it has no right to expect very high rewards. He has chosen security and peace of mind, so there will always be a limit to what he can earn. But a man who at-tempts to become a star is taking enormous risks. He knows at the outset that only a handful of competitors ever get to the very top. He knows that years of concentrated effort may be rewarded with complete failure. But he knows, too, that the rewards for success are very high indeed ： they are the payback for the huge risks involved and once he makes it, he will certainly earn them. That's the essence of private enterprise. The author develops the passage mainly by __________.
| A．comparing different ideas |
| B．giving explanations |
| C．inferring |
| D．listing typical examples |
The underlined word “begrudge" in the third paragraph is closest in meaning to __________.
A. be jealous of
B. be satisfied with
C. be anxious about
D, be crazy aboutAccording to the passage, which of the following can match the view of the author?
| A．He who laughs last laughs best. |
| B．If you venture nothing, you will gain nothing. |
| C．He who makes no mistakes makes nothing. |
| D．Success belongs to the persevering. |
The author holds a(n)__________ attitude towards the high income of pop stars.
| A．critical |
| B．approval |
| C．optimistic |
| D．indifferent |
Which of the following is true according to the passage?
| A．People are blind in idolizing stars. |
| B．There is fierce competition in becoming pop stars. |
| C．The government taxes pop stars very little. |
| D．Pop stars'life is more luxurious than that of royalty. |
New rules will let millions of Americans know where more of their food comes from. The law is known as COOL-Country of Origin Labeling.
American Congress first passed the law in 2002. Stores have had to label seafood by country-of-origin since 2005. But industry pressure delayed other requirements until last week.
Products that must now be labeled include fresh fruits and vegetables, muscle meats and some kinds of nuts. But the rules are complex, and many foods are excluded. For example, organ meats are free to be labeled. So are processed foods, including cooked or smoked food.
The United States has imported more and more food in recent years to save money and expand choices. Country-of-origin labeling has become more common lately but has still been limited in many stores.
Food safety is one reason why some shoppers pay close attention to where foods came from. For example, when a large number of people recently got sick from salmonella (沙门菌病），officials blamed peppers from Mexico. Yet the last big food scare involved spinach (菠菜）grown in California. But labeling is also a way for people to know they are getting what they want. Some want to buy local foods or foods from a particular country.
The country-of-origin labeling law gives stores 30 days to correct any violations that are found. Stores and suppliers that are found to be deliberately violating the law could be fined 1，000dollars per violation. Federal inspectors are not to take action to en-force the law for six months to give time for an education campaign.
Some food safety activists say they are generally pleased with the law. They call it a good step that will give people more useful information. What's the regulation in the new rules?
| A．Stores have to label food by its producing date from now on. |
| B．The country-of-origin labeling has to be marked on more food. |
| C．Stores have to label seafood by country of origin. |
| D．Labeling of food should include more useful information. |
Why has more and more food been imported to the United States in recent years?
| A．Because it is economical and provides people with more choices. |
| B．Because the United States is short of food supply. |
| C．Because Americans need more and more food recently. |
| D．Because foreign food is of higher quality than native food. |
Consumers are more concerned about where foods came from because __________.
| A．they are curious about the country of the food origin |
| B．they are particular about the tastes of the food |
| C．they are concerned about food safety and want to get what they want |
| D．most of the shoppers are food safety activists themselves |
The new rules of the country-of-origin labeling law will come into effect __________.
| A．right now |
| B．in a month |
| C．in three months |
| D．in half a year |
Which of the following can be inferred from the passage?
| A．Most Americans prefer imported vegetables to the vegetables grown in local places， |
| B．The government of America will forbid importing peppers from Mexico. |
| C．The law was not fully carried out until last week because of food industry's resistance. |
| D．Store owners are most likely to be the supporters of the law. |
Even plant can run a fever, especially when they're under attack by insects or disease. But unlike human, plants can have their temperature taken from 3，000 feet away straight up. A decade ago, adopting the infrared (红外线）scanning technology developed for military purposes and other satellites, physicist Stephen Paley came up with a quick way to take the temperature of crops to determine which ones are under stress. The goal was to let farmers precisely target pesticide (杀虫剂）spraying rather than rain poison on a whole field, which invariably includes plants that don't have pest(害虫）problems.
Even better, Foley's Remote Scanning Services Company could detect crop problems before they became visible to the eyes. Mounted on a plane flown at 3，000 feet at night, an infrared scanner measured the heat emitted by crops. The data were transformed into a color-coded map showing where plants were running " fevers". Farmers could then spot-spray, using 50 to 70 percent less pesticide than they otherwise would.
The bad news is that Paley's company closed down in 1984，after only three years. Farmers resisted the new technology and long-terra backers were hard to find. But with the renewed concern about pesticides on produce, and refinements in infrared scanning, Paley hopes to get back into operation. Agriculture experts have no doubt the technology works. " This technique can be used on 75 percent of agricultural land in the United States，" says George Oerther of Texas A & M. Ray Jackson, who recently retired from the Department of Agriculture, thinks remote infrared crop scanning could be adopted by the end of the decade. But only if Paley finds the financial backing which he failed to obtain 10 years ago. Plants will emit an increased amount of heat when they are __________.
| A．sprayed with pesticides |
| B．facing an infrared scanner |
| C．in poor physical condition |
| D．exposed to excessive sun rays |
In order to apply pesticide spraying precisely, we can use infra-red scanning to __________.
| A．estimate the damage to the crops |
| B．measure the size of the affected area |
| C．draw a color-coded map |
| D．locate the problem area |
Farmers can save a considerable amount of pesticide by __________.
| A．resorting to spot-spraying |
| B．consulting infrared scanning experts |
| C．transforming poisoned rain |
| D．detecting crop problems at an early stage |
The application of infrared scanning technology to agriculture met with some difficulties. For example，__________.
| A．the lack of official support |
| B．its high cost |
| C．the lack of financial support |
| D．its failure to help increase production |
Infrared scanning technology may be brought back into operation because of __________.
| A．the desire of farmers to improve the quality of their produce |
| B．growing concern about the excessive use of pesticides on crops |
| C．the forceful promotion by the Department of Agriculture |
| D．full support from agricultural experts |