When an ant dies, other ants take it out of the nest, often within an hour after its death. This behavior interests scientists and they wonder how ants know for sure—and so soon—that another ant is dead.
One scientist recently came up with a way to explain this ant behavior. Dong-Hwan Choe is a biologist, a scientist who studies animals and plants. He found that ants have a chemical on the outside of their bodies that signals to other ants, “I'm dead—take me away” when it is dead.
But there's a question to answer: As we know, if an ant is dead, it stops moving. But when an ant is sleeping or knocked unconscious, it is also not moving. However, other ants don't move the living ant out of the nest. How do they know this ant is not dead? Choe found that ants have another chemical on their bodies, which tells nearby ants something like, “Wait—I'm not dead yet” when it is not dead. Choe suspects that when an ant dies, the chemical that says, “Wait— I'm not dead yet” quickly goes away. When other ants detect the “dead” chemical without the “not dead yet” chemical, they move away the body.
To test his theory, Choe and his team put different chemicals on ants. When the scientists used the “I'm dead” chemical, other ants quickly moved the treated ant away. When the scientists used the “Wait—I'm not dead yet” chemical, other ants left the treated ant alone. Choe believes this behavior shows that the “not dead yet” chemical is stronger than the “dead” chemical when picked up by other ants. And that when an ant dies, the “not dead yet” chemical fades away. Other nearby ants then detect the remaining “dead” chemical and remove the body from the nest.
Understanding this behavior can help scientists figure out how to stop ants from invading new places and causing problems.What is the function of the first paragraph?
| A．Leading the following paragraphs. |
| B．Showing the main idea of the passage. |
| C．Introducing the background of the passage. |
| D．Giving a summary of the passage. |
What can we learn from the passage?
| A．Living ants can also be taken away when they are not moving. |
| B．When an ant dies, it can tell others using a certain chemical. |
| C．A living ant can pretend to be dead using a special chemical. |
| D．Ants often use chemicals to communicate with each other. |
Which of the following descriptions about Dong-Hwan Choe is right?
| A．Choe did this study in order to stop ants from invading new places. |
| B．Choe is a biologist who is only interested in animals, especially in ants. |
| C．Choe first came up with an idea to explain this ant behavior, and then did some tests to prove his theory. |
| D．Choe did the research on this ant behavior on his own. |
What is mainly discussed in the passage?
| A．experiments about how ants manage to keep their nests clean. |
| B．experiments about why ants have special chemicals on their bodies. |
| C．experiments about why ants can have this removal behavior |
| D．experiments about how to decide whether an ant is dead or not. |
Alibaba founder Jack Ma has become China's richest person according to a wealth survey by the． Hurun Report． Mr．Ma tops its annual rich list with a fortune of $25bn,．followed, by Wanda Group chairman Wang Jianlin．
Internet billionaires account for five of China's 10 richest people this year, beating property giants（房地产巨头） who have traditionally dominated（占优势） the list, which also includes the head of Tencent, Pony Ma．Other technology giants on the list include the co-founder of Chinese search group Baidu, Robin Li, and the founder of online retailer （零售商） JD．com, Richard Liu．
CHINARICH LIST
Hurun Report chairman and chief researcher Rupert Hoogewerf said, "Jack Ma is the 11th Number One we have had in China in the last 16 years, showing the dynamism（活力） of the Chinese economy, and an outstanding reminder of the growth potential that is being realized in the new markets"．
The Hurun Report's rich list is one of the most closely-watched and accurate assessments of wealth in China． The annual report has been published for the past 16 years． Individuals or families required at least $2．3bn this year to make it onto the list, which is more than 15 times the amount needed a decade ago． There are a record 354 so-called "dollar billionaires" in China this year, Hurun said, which is a 13% increase from last year．Overall, the total wealth of the l,271 people on the list is worth $1．4tn this year
Hurun said it had been "an amazing year" for the online retail and other IT sectors and a “good year” for entertainment, investments, cars, renewable energy, pharmaceuticals（药业） and manufacturing． On the other side, Hurun said it had "been a bad year for steel and shipping" and that real estate（不动产） "could have done a lot worse, bearing in mind the state of the market"．
The world's second-largest economy has been slowing down． Its property industry may
have 'overheated and that levels of local debt are too high． As a result, the government has taken measures to cool the housing market, which has slowed down for several quarters．Perhaps reflecting this shift, four of the six property giants in last year's top 10 list have dropped down the rankings．According to Rupert Hoogewerf, Jack Ma's being the 11th richest in China in the last 16 years indicates that．
| A．China will surely have the 12ffi Number One next year |
| B．the growth of China's economy in the last 16 years is incredible |
| C．new markets are providing China with great potential for economic growth |
| D．China has successfully sailed through the global financial crisis started in 2008 |
What is true about the Hurun Report's rich list?
| A．Accurate assessments lend credit to the rich list． |
| B．Only individual billionaires can make it onto the list． |
| C．The list has been published every other year for 16 years． |
| D．It favors investments and cars rather than steel and shipping． |
What can be inferred from the changes in the top 10 list during the past two years?
| A．Property giants are no longer rich due to the shift． |
| B．China has become the world's second-largest economy． |
| C．Internet billionaires traditionally dominated the top 10 list． |
| D．The Government has played a role in the changes of house prices． |
Good news for middle and high school students． When it comes to sleeping a little longer, physicians are on your side．
On Monday, the American Academy Pediatrics（儿科） announced its recommendation that middle and high schools start at 8:30 a．m．or later． "Doing so will match school schedules to the biological sleep patterns of adolescents," the AAP writes in a press release regarding its new policy statement called “School Start Times for Adolescents" ．
"Chronic（慢性的） sleep loss in adolescents is one of the most common public health issues in the U．S．today," according to Judith Owens, director of Sleep Medicine at Children's National Health System．
"The research is clear that adolescents who get enough sleep have a reduced risk of being overweight or suffering depression, are less likely to be involved in automobile accidents, and have better grades, higher standardized test scores and an overall better quality of life," Owens said in the press release． "Studies have shown that delaying early school start times is one key factor that can help adolescents get the sleep they need to grow and learn．"
Even before the AAP's announcement, school districts across the country have been rethinking start times． Earlier this year The New York Times wrote about Dos Santos, a student at Rock Bridge High School． When Dos Santos learned that school officials were considering starting school 30 minutes earlier than the existing time, she became worried．The student gathered others to her cause． In the end, school officials decided against the earlier start time．
One of the organizations that Dos Santos reached out to for help was Start School Later, a nonprofit organization that focuses on getting public schools to set "healthy school hours．"
"It's going to take collective action, perhaps on a national scale, to get many districts to take on this issue," Terra Ziporyn Snider, PhD, director and co-founder of Start School Later, told Yahoo Health．
"The science is clear, the will to change isn't," she explained． "The reason for that is that community life goes around school schedules, and any suggestion of change - earlier, later, whatever - brings powerful opposition from everyone who fears a change in routine．"What can be learned about Start School Later?
| A．Dr．Snider is director of this nonprofit organization． |
| B．It is a commercial organization belonging to Yahoo Health． |
| C．It helps private schools to set healthy schedules for students． |
| D．It made a policy called。‘School Start Times for Adolescents"． |
Which of the following is NOT mentioned as benefit from enough sleep?
| A．Students will enjoy a better life． |
| B．Students might feel less depressed． |
| C．Students may achieve higher grades． |
| D．Students are more likely to be on time for school． |
What can be inferred from the last paragraph?
| A．Scientific findings are not convincing． |
| B．Changing school start time is no easy job． |
| C．Most people are willing to change schedules． |
| D．The revolution of school schedules is under way． |
People talk about energy everywhere. Green energy, for example. Then, energy independence. It has a nice ring to it. Doesn’t it? If you think so, you’re not alone, because energy independence has been the dream of American president for decades, and never more so than in the past few years, when the most recent oil price shock has been partly responsible for kicking off the great recession(经济衰退).
"Energy independence" and its rhetorical(修辞的) companion "energy security" are, however, unreliable concepts that are rarely thought through. What is it that we want independence from, exactly?
Most people would probably say that they want to be independent from imported oil. But there are reasons that we buy all that oil from elsewhere.
The first reason is that we need it to keep our economy running. Yes, there is a trickle(涓涓细流) of biofuel(生物燃料) available, and more may become available, but most biofuels cause economic waste and environmental destruction.
Second, Americans have basically decided that they don’t really want to produce all their own oil. They value the environmental quality they preserve over their oil imports from abroad. Vast areas of the United States are off-limits to oil exploration and production in the name of environmental protection. To what extent are Americans really willing to tolerate the environmental influence of domestic(国内的) energy production in order to cut back imports?
Third, there are benefits to trade. It allows for economic efficiency, and when we buy things from places that have lower production costs than we do, we benefit. And although you don’t read about this much, the United States is also a large exporter of oil products, selling about 2 million barrels of petroleum products per day to about 90 countries.
There is no question that the United States imports a great deal of energy and, in fact, relies on that steady flow to keep its economy stable. When that flow is interrupted, we feel the pain in short supplies and higher prices. At the same time, we get massive economic benefits when we buy the most affordable energy on the world market and when we engage in energy trade around the world.What does the author say about energy independence for America?
| A．It sounds very attractive. |
| B．It ensures national security. |
| C．It will bring oil prices down. |
| D．It will protect the environment. |
Why does America rely heavily on oil imports?
| A．It wants to expand its storage of raw oil. |
| B．Its own oil reserves are quickly running out. |
| C．Its own oil production falls short of demand. |
| D．It wants to keep its own environment untouched. |
What does the author say about oil trade?
| A．It improves economic efficiency. |
| B．It makes for economic recession. |
| C．It brings benefit only to the sellers. |
| D．It saves the cost of oil exploration. |
What is the author’s purpose in writing the passage?
| A．To explain the increase of international oil trade. |
| B．To raise Americans' awareness of the energy crisis. |
| C．To argue for America’s dependence on oil imports. |
| D．To stress the importance of energy protection. |
Whenever people think of charity, the first word that jumps into their mind may be money donated to the needy. However, Wugging, or web-use giving, describes the act of giving to charity at no cost to the user. By using Everyclick. com, which is being added to a number of university computers across the UK, students can raise money every time they search, but it won’t cost them a penny.
Research shows that students are extremely enthusiastic about supporting charity--88% of full time students have used the Internet to give to charity. This figure is high considering this age group is often the least likely to have their own income. 19% of 22 to 24 year olds have short-term debts of more than & 5, 000. With rising personal debt levels in this age group, due to university tuition fees or personal loans and a lack of long-term savings, traditional methods of donating to charity are often not appealing or possible.
Beth Truman, a 21-year-old recent university graduate, has used Everyclick. com to donate to her chosen charity, the RSPCA, for two years and has seen the "Wugging" grow in popularity with students. "When you’re at university you become more socially aware, but it’s sometimes hard to give to others when you have little money yourself," says Beth. "Wugging is great for people in this age group as it allows them to use the technology on a daily basis to give to charity, without costing them a single penny."
Wugging is perfect for people who want to be more socially aware and supportive but don’t feel they have the means to do so. Students using the web can raise money for causes they care about without costing them anything in terms of time or money, and charities get a valuable source of funding.
Everyclick. com works like any other search engine, allowing users to search for information, news and images but users can decide which of the UK’s 170, 000 charities they would like to support through their clicks. Everyclick. com then makes monthly payments to every registered charity. Launched in June 2005, Everyclick. com is now the eighth largest search engine and one of the busiest charity websites in the UK.According to the passage, "Wugging" is actually____.
| A．a charity-related action |
| B．a website |
| C．a school organization |
| D．a student movement |
In the case of charity, Everyclick. com____.
| A．receives much money from students |
| B．frees students of the financial worries |
| C．offers valuable information to students |
| D．praises students for their money-raising |
From the passage, we can conclude that____.
| A．most full time students do charity on the Internet every day |
| B．Everyclick. com is the busiest charity website in the UK |
| C．Everyclick. com helps students pay for further education |
| D．"Wugging" is a win-win idea for both students and charities |
What would be the best title for the passage?
| A．"Wugging", a popular term on the Internet |
| B．Students collect money for charity by "Wugging" |
| C．More British charities benefit from the Internet |
| D．Charity enjoys increasing popularity with the British |
People laugh and people cry. But it is thought that emotions such as anger, or joy, typically make Americans feel uncomfortable and embarrassed. The shedder of tears(落泪者) is likely to apologize, even when a great tragedy was the cause. The observer of tears is likely to do everything possible to put an end to the emotional tears. But judging from recent studies of crying behavior, both those responses to tears are often inappropriate and may even be counterproductive (适得其反).
Humans are the only animals clearly known to shed emotional tears. Since evolution has given rise to few purposeless physiological responses, it is logical to assume that crying has one or more functions that increase survival.
Although some observers have suggested that crying is a way to ask for assistance form others (as a crying baby might from its mother), the shedding of tears is hardly necessary to get help. Vo-cal (出声的) cries would have been quite enough, more likely than tears to gain attention. So, it appears that there must be something special about tears themselves.
Indeed, the new studies suggest that emotional tears may play a direct role in easing stress. University of Minnesota researchers who are studying the chemical composition of tears have recently separated two important chemicals from emotional tears. Both chemicals are found only in tears that are shed in response to emotion. Tears shed because of exposure to cut onion would contain no such substance.
Other researchers are looking into the usefulness of tears as a means of diagnosing human ills and monitoring drugs. At Tulane University’s Teat Analysis Laboratory Dr. Peter Kastl and his colleagues report that they can use tears to detect drug abuse, to study the causes of "dry eye" syndrome(综合症) and the effects of eye surgery, and perhaps even to measure exposure to environmental pollutants.What does the phrase "both those responses" in Paragraph 1 refer to?
| A．Crying out of sorrow and shedding tears for happiness. |
| B．The embarrassment and unpleasant feelings of the observers. |
| C．Linking illness with crying and finding the chemical composition of tears. |
| D．The tear shedder’s apology and the observer’s effort to stop the crying. |
It is known from the first paragraph that____.
| A．shedding tears gives unpleasant feelings to Americans |
| B．crying may often result in tragedy |
| C．crying usually wins sympathy from other people |
| D．one who sheds tears in public will be blamed |
What does the author say about crying?
| A．It is a pointless physiological response to the environment. |
| B．It must have a role to play in man' s survival. |
| C．It is meant to get attention and assistance. |
| D．It usually produces the desired effect. |
From the passage we can infer that____.
| A．it is unnatural for people to shed tears |
| B．we can reduce our stress by shedding tears |
| C．shedders of tears can' t get help by crying loudly |
| D．unlike animals, humans can shed tears for survival |