The world's first hydrogen-powered trains have begun running in Germany. They began carrying passengers Monday in Germany's northern Lower Saxony state. The new train will run 100-kilometer trips and can travel up to 140 kilometers an hour.
A French railroad company called Alstom built the two trains. Team in Germany and France cooperated on the project, which was supported by the German government. The new train model ,called the Coradia ilint, signals the beginning of efforts in Germany and other nations to move away from pollution-producing diesel(柴油) trains.
The Coradia iLint is designed to run on non-electrified train lines with low levels of noise.
It uses a process that combines hydrogen and oxygen to produce electrical power. If the system produces more energy than the train needs at that time, it can store the extra energy in batteries. The only emissions (排放物) are water and steam.
A single tank of hydrogen can run a Coradia iLint train for about 1,000 kilometers. This is very similar to the distance a diesel-powered train can run on with a single tank.
Hydrogen-powered trains cost more than diesel trains to build. But Alstom officials say the operating costs are much lower. The company plans to provide another 14 Coradia iLint trains to Lower Saxony by 2021.
The head of railroad operations in the area, Carmen Schwab, praised replacing diesel trains with hydrogen. She said the move was an important first step in using clean-burning technologies to reach climate protection goals.
Officials say the area's many wind turbines (涡轮机)will produce part of the energy to create the hydrogen to power the trains.
Alstom says several other European countries have also expressed interest in developing hydrogen train systems. France has already said it wants its first hydrogen train to be operating by 2022.
1.Why did Germany build the new trains?
A. To replace diesel trains.
B. To carry more passengers.
C. To make traveling much easier.
D. To develop friendship with France.
2.What is one advantage of the Coradia iLint?
A. It runs without making any noise.
B. It doesn't use electrical power.
C. It costs much less to run.
D. It is cheaper to make it.
3.It can be concluded that hydrogen trains________.
A. are widely used
B. are environmentally friendly
C. can stop air pollution
D. can produce water and oxygen
4.What might be the best title for the text?
A. Saving Natural Resources
B. Efforts to Reduce Emissions
C. World's First Hydrogen Trains
D. A New Way to Make Electricity
It might sound like a terrible dream,but a new design from Dubai-based airline Emirates plans to remove windows from airplanes. Instead of real-life views of clouds and sky, first-class passengers will look out of “virtual(虚拟的)windows,” enjoying projected views of the world passing by. Emirates’ “windows” use real time high-tech camera technology to provide virtual views of the outside world.
Saj Ahmad,Chief analyst at Strategic Aero Research says,”Windowless airplanes sound great-however, in reality, it won’t happen for a number of reasons. For starters,in the event of an emergency,people in the plane often need to look out for reference points. Having visual awareness is important and in a windowless jet, they don’t exist-especially if there is an electrical fault which then means that the ‘electric’ windows do not work and you can’t see outside.” Ahmad was also concerned about passenger comfort. “Passengers simply do love the natural view outside,” he says. “There are also other problems---the change involved would certainly require new tests.”
Other futuristic airplane designs are going the opposite way. Boeing’s Dreamliner ---its most modern design---features large windows. Airbus has also designed a plane with transparent(透明的) walls that is presented at the 2011 Paris Air Show. Embraer has planned the Kyoto cabin, designed for its Lineage 1000E aircraft, which features large windows running along the majority of the walls of the cabin.
There could also be a move towards pilotless planes in the future---but Ahmad applies his doubts about windowless planes to drone-flown(无人驾驶的) planes too. “The idea of windowless planes is possible---that doesn’t mean it will happen,” says Ahmad. “The same applies to drone technology---but that doesn’t mean that tomorrow we’re suddenly going to see all airplanes being flown without pilots.”
1.What will Emirates’ new planes be like?
A.They will be pilotless.
B.They will have open windows.
C.They will present outside views on virtual windows.
D.They will provide all passengers with windowless experiences.
2.What does Saj Ahmad think of the virtual windows?
A.Useful. B.Expensive. C.Impractical. D.Comfortable.
3.How is the third paragraph developed?
A.By giving examples. B.By making comparisons.
C.By following space order. D.By explaining cause and effect.
4.What is the future of drone technology according to Saj Ahmad?
A.It needs more skilled engineers. B.It will take time to develop.
C.It will be widely applied. D.It is promising.
Google previously announced successful tests of machine learning systems designed to assist doctors. In one case, Google reported AI had examined eye diseases with equal accuracy to doctors. Other tests showed that machine learning can be used to study large amounts of patient data to predict future medical events.
Now the company has published two new studies showing a high level of success in identifying metastatic breast cancer. Metastatic means that cancer has spread from its main area to other parts of the body. Metastatic breast cancer is one of the deadliest, causing about 90 percent of all breast cancer deaths worldwide.
In metastatic breast cancer patients, the cancer often travels to nearby lymph nodes(淋巴结). Usually doctors examine lymph node tissue under a microscope to see whether cancer is present. Google notes that previous studies have shown that up to one-fourth of metastatic lymph node classifications end up being changed after a second examination. In addition, studies show that small metastatic material can be missed up to 67 percent of the time when examinations happen under extreme time restrictions.
Google says it created a mathematical algorithm(算法). The algorithm, called Lymph Node Assistant, is trained to find characteristics of tissue affected by metastatic cancer. When the system examined tissue images(图像), it was able to differentiate between metastatic cancer and non-cancer 99 percent of the time. In addition, the Lymph Node Assistant is highly effective at finding the positions of the cancers. Some of these positions would be too small for doctors themselves to identify. The research also showed that the algorithm method can reduce the usual time needed to examine the disease by about 50 percent.
But Google makes clear the AI-based system is not meant to replace the work of medical professionals. Instead, it is designed to reduce the number of false identifications and help doctors work faster and more effectively.
1.What is the main idea of Paragraph 1?
A.Google became a pioneer in training doctors.
B.Machine learning is able to stop future medical events.
C.Google developed artificial intelligence to help doctors.
D.Artificial intelligence cured eye diseases with equal accuracy to doctors.
2.What can we infer about metastatic breast cancer?
A.One-fourth of the metastatic breast cancer patients die in the end.
B.Metastatic breast cancer is very difficult to identify.
C.It results in 90 percent of deaths of all cancers.
D.It can be identified after a second examination.
3.What is the advantage of Google’s new mathematical algorithm?
A.It can offer effective treatment.
B.It can tell the exact positions of cancers
C.It costs 99 percent less time than before.
D.It improves the accuracy of identifying cancers by 50%.
4.What influence will the mathematical algorithm bring?
A.False identification of cancers will be avoided.
B.More effective prevention of cancers will be found.
C.The number of medical professionals will be reduced.
D.Doctors can have a faster understanding of patients’ condition.
Amazing Scientists
Who Happen to Be Teenagers
We’ve got a list of teen scientists from a variety of fields.
Jack Andraka
Jack Andraka created a biosensor for cancer that he says is 168 times faster, 26,667 times less expensive and 400 times more sensitive than technology nowadays.
He’s the youngest person to have spoken in front of the Royal Society of Medicine.
Taylor Wilson
Taylor Wilson was the youngest person to achieve nuclear fusion(核聚变). He was inspired by The Radioactive Boy Scout, a novel in which a kid tries and fails to build a nuclear reactor.
Taylor thought he could do better.Long story short, he wanted to build a small nuclear reactor. And he did it at the age of fourteen. He received a Thiel Fellowship, which gave him $100,000 to work on his own research.
Sara Volz
Sara Volz performed experiments in which she grew algae(藻类)based on their oil output for the purpose of growing them as biofuel. This research is especially important as the world continues to search for a way to lessen our dependence on non-renewable energy. She won the top prize of $100,000 in the lntel Science Talent Search.
Daniel Burd
Plastic usually takes thousands of years to decompose(降解)，but this high school student Daniel Burd managed to do it in three months.
In an experiment，he mixed plastic bags and a special kind of dirt together, and found that they did decompose faster.He then performed tests to find the bacteria(细菌)responsible for decomposing the plastics.
His solution only produces water and small amounts of carbon dioxide.He says it could easily be used elsewhere.
1.Who designed a medical instrument?
A.Sara Volz. B.Daniel Burd. C.Jack Andraka. D.Taylor Wilson.
2.What excited Taylor Wilson’s interest in his invention?
A.A novel by a kid. B.Plastic pollution.
C.Energy shortage. D.A story book.
3.What do we know about Daniel Burd’s invention?
A.It won him a $100,000 prize. B.It does little harm to the environment.
C.It was completed in three months. D.It is widely used in everyday waste.
听下面一段独白，回答以下小题。
1.At what age did Emily start learning ballet?
A.Five. B.Six. C.Nine.
2.Why did Emily move to Toronto?
A.To work for a dance school.
B.To perform at a dance theater.
C.To learn contemporary dance.
3.Why did Emily quit dancing?
A.She was too old to dance.
B.She failed to get a scholarship.
C.She lost interest in it.
4.How does Emily feel about stopping training?
A.She’s pleased. B.She’s regretful. C.She’s upset.
听下面一段较长对话，回答以下小题。
1.Who is Macy?
A.Ed’s mother. B.Ed’s teacher. C.Ed’s friend.
2.How does Ed usually go to kindergarten?
A.By car. B.On foot. C.By bus.
3.What does Ed enjoy doing at the kindergarten?
A.Telling stories. B.Singing songs. C.Playing with others.
4.What do the teachers say about Ed?
A.He’s clever. B.He’s quiet. C.He’s brave.
