单选题Smoking is not {{U}}permitted{{/U}} in the office.
单选题On the contrary, the boy is such a courageous boy.A. foolishB. smartC. braveD. excellent
单选题
阅读下面这篇短文,短文后列出了7个句子,清根据短文的内容对每个句子作山判断。如果该句提供的是正确信息,请选择A项;如果该句提供的是错误信息,请选择B项;如果该句的信息文章中没有提及,请选择C项。
{{B}}El Nino{{/B}} While
some forecasting methods had limited success predicting the 1997 El Nino a few
months in advance, the Columbia University researchers say their method call
predict large El Nino events up to two years in advance. That would be good news
for governments, farmers and others seeking to plan for the droughts and heavy
rainfall that El Nino can produce in various parts of the world.
Using a computer the researchers matched sea-surface temperatures to later
El Nino occurrences between 1980 and 2000 and were then able to anticipate El
Nino events dating back to1857, using prior sea-surface temperatures. The
results were reported in the latest issue of the journal Nature.
The researchers say their method is not perfect, but Bryan C. Weare. a
meteorologist at the University of California, Davis, who was not involved in
the work, said it "suggests'El Nino is indeed predictable.'"
"This will probably convince others to search around more for even better
methods." said Weare. He added that the new method "makes it possible to predict
El Nino at long lead.times." Other models also use sea-surface temperatures, but
they have not looked as far back because they need other data, which is only
available for recent decades, Weare said. The ability to predict
the warming and cooling of the Pacitic is of immense importance. The 1997 El
Nino, for example, caused an estimated $ 20 billion in damage worldwide, offset
by beneficial effects in other areas, said David Anderson, of the European
Centre for Medium Range Weather Forecasts in Reading England. The 1877 El Nino,
meanwhile, coincided with a failure of the Indian monsoon and a famine that
killed perhaps 40 million in India and China, prompting the development of
seasonal forecasting, Anderson said. When El Nino hit in 1991
and 1997, 200 million people were affected by flooding in China alone, according
to a 2002 United Nations report. While predicting smaller El
Nino events remains tricky, the ability to predict larger ones should be
increased to at least a year if the new method is confirmed. El
Nino tends to develop between April and June and reaches its peak between
December and February. The warming tends to last between 9 and 12 months and
occurs every two to seven years The new forecasting method does
not predict any major El Nino events in the next two years, although a weak
warming toward the end of this year is possible. El Ninon.
厄尔尼诺现象 equatorial adj.赤道的 occurrence n.
发生 meteorologist n.气象学家 offset v. 抵销
lead adj. 提前的 monsoon n.季风 tricky
adj.难以捉摸的
单选题{{B}}第二篇{{/B}}
{{B}}
Media and Current Events{{/B}} The media can impact
current events. As a graduate student at Berkeley in the 1960s, I remember
experiencing the events related to the People’s park that were occurring on
campus. Some of these events were given national media coverage in the press and
on TV. I found it in teresting to compare my impressions of what was going on
with perceptions obtained from the news media. I could begin to see events of
that time feed on news coverage. This also provided me with some healthy
insights into the distinctions between these realities.
Electronic media are having a greater impact on the people’s lives every
day. People gather more and more of their impressions from representations.
Television and telephone communications are linking people to a global village,
or what one writer calls the electronic city. Consider the information that
television brings into your home every day. Consider also the contact you have
with others simply by using telephone. These media extend your consciousness and
your contact. For example, the video coverage of the 1989 San Francisco
earthquake focused on “live action” such as the fires or the rescue efforts.
This gave the viewer the impression of total disaster. Television coverage of
the Iraqi War also developed an immediacy. CNN reported events as they happened.
This coverage was distributed worldwide. Although most people were far away from
these events, they developed some perception of these realities.
In 1992, many people watched in horror as riots broke out on a sad
Wednesday evening in Los Angeles, seemingly fed by video coverage from
helicopters. This event was triggered by the verdict (裁定) in the Rodney King
beating. We are now in an age where the public can have access to information
that enables it to make its own judgements, and most people, who had seen the
video of this beating, could not understand how the jury (陪审团) was able to
acquit (宣布无罪) the policemen involved. Media coverage of events as they occur
also provides powerful feedback that influences events. This can have harmful
results, as it seemed on that Wednesday night in Los Angeles. By Friday night
the public got to see Rodney King on television pleading, “Can we all get
along?” By Saturday, television seemed to provide positive feedback as the Los
Angeles riot turned out into a rally for peace. The television showed thousands
of people marching with banners and cleaning tools. Because of that, many more
people turned out to join the peaceful event they saw unfolding (展开) on
television. The real healing, of course, will take much longer, but electronic
media will continue to be a part of that
process.
单选题The committee comprises five persons. A. absorbs B. concems C. excludes D. involves
单选题The new Greenpeace card breaks down in a few months.
单选题With immense relief, I stopped running. A. some B. enormous C. little D. extensive
单选题Putting Plants to Work Using the power of the sun is nothing new. People have had solar-powered calculators and buildings with solar panels for decades. But plants are the real experts: They've been using sunlight as an energy source for billions of years. Ceils in the green leaves of plants work like tiny factories to convert sunlight, carbon dioxide, and water into sugars and starches, stored energy that the plants can use. This conversion process is called photosynthesis. Unfortunately, unless you're a plant, it's difficult and expensive to convert sunlight into storable energy. That's why scientists are taking a closer look at exactly how plants do it. Some scientists are trying to get plants, or biological cells that act like plants, to work as miniature photosynthetic power stations. For example, Mafia Ghirardi of the National Renewable Energy Laboratory in Golden, Colo., is working with green algae. She's trying to trick them into producing hydrogen instead of sugars when they perform photosynthesis. Once the researchers can get the algae working efficiently, the hydrogen that they produce could be used to power fuel cells in cars or to generate electricity. The algae are grown in narrow-necked glass bottles to produce hydrogen in the lab during photosynthesis, plants normally make sugars or starches. "But under certain conditions, a lot of algae are able to use the sunlight energy not to store starch, but to make hydrogen." Ghirardi says. For example, algae will produce hydrogen in an air free environment. It's the oxygen in the air that prevents algae from making hydrogen most of the time. Working in an air free environment, however, is difficult. It's not a practical way to produce cheap energy. But Ghirardi and her colleagues have discovered that by removing a chemical called sulfate from the environment that the algae grow in, they will make hydrogen instead of sugars, even when air is present. Unfortunately, removing the sulfate also makes the algae's cells work very slowly, and not much hydrogen is produced. Still, the researchers see this as a first step in their goal to produce hydrogen efficiently from algae. With more work, they may be able to speed the cells' activity and produce larger quantities of hydrogen. The researchers hope that algae will one day be an easy-to-use fuel source. The organisms are cheap to get and to feed, Ghirardi says, and they can grow almost anywhere: "You can grow them in a reactor, in a pond You can grow them in the ocean. There's a lot of flexibility in how you can use these organisms. /
单选题Human Space Exploration While scientists are searching the cause of the Columbia disaster, NASA is moving ahead with plans to develop a new craft that would replace shuttles(航开飞机)on space station missions by 2012 and respond quickly to space station emergencies. The space agency released the first set of mission needs and requirements several days ago for me orbital space plane(轨道航天飞机), which would be designed to transport a crew of four to and from the International Space Station. Although it includes few specifics, the plan states the orbiter(轨道航天飞机)will be safer cheaper and require less preparation time than the shuttle. It would be able to transport four crew members by 2012--though it would be available for rescue missions by 2010 NASA says the craft should be able to transport injured or ill space station crew- members to "definitive(决定性的) medical care" within 24 hours. The release of the requirements showed NASA remains focused on the long-term priorities of space exploration, even as questions exist concerning the loss of Columbia and its seven, member crew- on February 1, 2003. Expels at Marshall Space Flight Center in Huntsville, Alabama, have been working for years on a successor to the shuttle. The project, known as the Space Launch Initiative(倡议), was divided last year into two parts----one focusing on a future launch vehicle, the other on a space station orbiter. The orbiter is expected to be ready sooner. The program's managers say NASA officials have told them not to alter Space Launch Initiative in light of the Columbia disaster. U. S. President George W: Bush asked Congress for about US$1 billion for Space Launch Initiative in 2004, funds that would be almost equally split between the Orbital Space Plane and Next Generation Launch Technology.
单选题Teaching Math, Teaching Anxiety In a new study about the way kids learn math in elementary school, the psychologists at the University of Chicagol Sian Beilock and Susan Levine found a surprising relationship between what female teachers think and what female students learn: If a female teacher is uncomfortable with her own math skills, then her female students are more likely to believe that boys are better than girls at math. "If these girls keep getting math-anxious female teachers in later grades, it may create a snowball effect on their math achievement," said Levine. In other words, girls may end up learning math anxiety from their teachers. The study suggests that if these girls grow up believing that boys are better at math than girls are, then these girls may not do as well as they would have if they were more confident. Just as students find certain subjects to be difficult, teachers can find certain subjects to be difficult to learn—and teach. The subject of math can be particularly difficult for everyone. Researchers use the word "anxiety" to describe such feelings: anxiety is uneasiness or worry. The new study found that when a teacher has anxiety about math, that feeling can influence how her female students feel about math. The study involved 65 girls, 52 boys and 17 first-and second-grade teachers in elementary schools in the Midwest. The students took math achievement tests at the beginning and end of the school year, and the researchers compared the scores. The researchers also gave the students tests to tell whether the students believed that a math superstar had to be a boy. Then the researchers turned to the teachers: To find out which teachers were anxious about math, the researchers asked the teachers how they felt at times when they came across math, such as when reading a sales receipt. A teacher who got nervous looking at the numbers on a sales receipt, for example, was probably anxious about math. Boys, on average, were unaffected by a teacher's anxiety. On average, girls with math- anxious teachers scored lower on the end-of-the-year math tests than other girls in the study did. Plus, on the test showing whether someone thought a math superstar had to be a boy, 20 girls showed feeling that boys would be better at math—and all of these girls had been taught by female teachers who had math anxiety. "This is an interesting study, but the results need to be interpreted as preliminary and in need of replication with a larger sample," said David Geary, a psychologist at the University of Missouri in Columbia.
单选题"Salty" Rice Plant Boosts Harvests
British scientists are breeding a new generation of rice plants that will be able to grow in soil containing salt water. Their work may enable abandoned farms to become productive once more.
Tim Flowers and Tony Yeo, from Sussex University"s School of Biological Sciences, have spent several years researching how crops, such as rice, could be made to grow in water that has become salty.
The pair have recently begun a three-year programme, funded by the Biotechnology and Biological Sciences Research Council, to establish which genes enable some plants to survive salty conditions. The aim is to breed this capability into crops, starting with rice.
It is estimated that each year more than 10m hectares (公顷) of agricultural land are lost because salt gets into the soil and stunts (妨碍生长) plants. The problem is caused by several factors. In the tropics, mangroves (红树林) that create swamps (沼泽) and traditionally formed barriers to sea water have been cut down. In the Mediterranean, a series of droughts have caused the water table to drop, allowing sea water to seep (渗透) in. In Latin America, irrigation often causes problems when water is evaporated (蒸发) by the heat, leaving salt deposits behind.
Excess salt then enters the plants and prevents them functioning normally. Heavy concentrations of minerals in the plants stop them drawing up the water they need to survive.
To overcome these problems, Flowers and Yeo decided to breed rice plants that take in very little salt and store what they do absorb in cells that do not affect the plants" growth. They have started to breed these characteristics into a new rice crop, but it will take about eight harvests before the resulting seeds are ready to be considered for commercial use.
Once the characteristics for surviving salty soil are known, Flowers and Yeo will try to breed the appropriate genes into all manners of crops and plants. Land that has been abandoned to nature will then be able to bloom again, providing much needed food in the poorer countries of the world.
单选题The chemical is {{U}}deadly{{/U}} to rats but safe to cattle.
A. fatal
B. hateful
C. good
D. useful
单选题{{U}}On behalf of{{/U}} everyone in this party, I wish you a very happy birthday.
单选题This tape-recorder has a tape-slide {{U}}facility{{/U}}.
单选题I hope that I didn't do anything absurd last night. A. awkward B. strange C. stupid D. awful
单选题We have thought varied ways to handle the problemA. sameB. differentC. manyD. few
单选题Which of the following about the ladle shaped compass is true?
单选题What does fossil and molecular evidence tell us about our earliest ancestors?
单选题{{B}}第三篇{{/B}}
Electronic Teaching The
potential of closed-circuit television and other new electronic teaching tools
is so great that it is fascinating to visualize "the school of
tomorrow". Televised lessons will originate from a
central building having perhaps four or five master studios. The lessons will be
carried into classrooms all over a city, or even an entire country.
After a televised lesson has been given, the classroom teacher will take
over for the all important "follow-up" period. The students will ask any
troublesome questions, and difficult points will be cleared up through
discussion. The teacher in the classroom will have additional
electronic tools. On the teacher's desk, the traditional chalk and erasers will
have been replaced by a multiple-control panel and magnetic tape player. The
tape machines will run pre recorded lessons which pupils will follow by
headphones. The lessons will be specifically geared to the students' levels of
ability. For instance, while the class as a whole studies history, each student
will receive an individual history lesson, directed to his particular level of
ability. Should question arise, the students will be able to
talk directly to the teacher on individual "intercoms" without disturbing the
rest of the class. In this way, the teacher will be able to conduct as many as
three classes at the same time. With the rapid development of
computer science, students will be aided with specially prepared multimedia
software to study their subjects better. Homework will possibly be assigned and
handed in via electronic mail system. Students can even take examinations on
their computer linked with the teacher's and get the score instantly. They will
get certificates or diplomas if they pass all the required examinations. Experts
believe that this type of education will be very popular in the years
ahead.
单选题The reason for their unusual behavior remains a Upuzzle/U.
