What will power your house in the future? Nuclear, wind, or solar power? According to scientists at the Massachusetts Institute of Technology(MIT) in the US, it might be leaves-but artificial(人造的)ones.
Natural leaves are able to change sunlight and water into energy. It is known as photosynthesis(光合作用). Now researchers have found a way to imitate this seemingly simple process.
The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a special silicon chip with catalysts(催化剂). Similar to natural leaves, it can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases are then stored in a fuel cell, which uses those two materials to produce electricity, located either on top of a house or beside the house.
Though the leaf is only about the shape of a poker card, scientists claimed that it is promising to be an inexpensive source of electricity in developing countries. "One can imagine villages in India and Africa not long from now purchasing an affordable basic power system based on this technology," said Nocera at a conference of the American Chemical Society.
The artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but was too expensive and unstable for practical use. The new leaf, by contrast, is made of cheap materials, easy to use and highly stable. In laboratory studies, Nocera showed that an artificial leaf prototype (原型)could operate continuously for at least 45 hours without a drop in activity.
The wonderful improvements come from Nocera's recent discovery of several powerful, new and inexpensive catalysts. These catalysts make the energy transformation inside the leaf more efficient with water and sunlight. Right now, the new leaf is about 10 times more efficient at carrying out photosynthesis than a natural one. Be-sides, the device can run in whatever water is available; that is, it doesn't need pure water. This is important for some countries that don't have access to pure water.
With the goal to " make each home its own power station" and" give energy to the poor",scientists believe that the new technology could be widely used in developing countries, especially in India and rural China. Which of the following orders correctly shows how the artificial leaf is used to produce electricity?
a. artificial leaves split water into hydrogen and oxygen
b. the hydrogen and oxygen gases are stored in a fuel cell
c. the artificial leaves are put in water
d. the fuel cell uses hydrogen and oxygen to produce electricity
A.c, b,a, d |
B.c, a,b, d |
C.b, c,a, d |
D.c, a,d, b |
The purpose of the scientists at MIT in developing the new artificial leaf is to __________.
A.build up more power stations in the world |
B.provide cheaper energy for developing countries |
C.offer people in developing countries access to pure water |
D.gain a deeper understanding of the photosynthesis process |
The main idea of this passage is __________.
A.an introduction to the history of artificial leaves |
B.an invention copying photosynthesis |
C.giving energy to the poor |
D.mixture of water power and solar energy |
The underlined word " imitate" in Paragraph 2 can be replaced by "__________".
A.produce |
B.hold |
C.prevent |
D.copy |
EVENTS
Long March exhibition
The Shanghai History Museum is putting on an exhibition to mark the 60th anniversary of the Long March.On show are more than 220 photos and 40 items that explain with pictures how the communist Red Army drew back from its besieged(被围困的) bases in Jiangxi Province and fought its way to northern Shanxi Province in the mid-1930s.Explanations are all in Chinese.The show will end on November 20.
Time: 10:00 am-4:00 pm
Address: 1286 Hongqiao Road
Admission: 8 yuan for Chinese /15 yuan for foreigners
Thai elephants
Eight elephants from Thailand are entertaining visitors at Changfeng Park by riding bikes, playing basketball, balancing on a pole, dancing and blowing a mouthorgan(口琴).People are encouraged to have a tug-of-war(拔河比赛)with the animals or lie on the ground and have the elephants walk over them.The elephants give three shows a day at 9:30 am, 3:30 pm and 8:00 pm and there is an additional show at l:30 pm at weekends.The show will end on November 15.
Address: 189 Daduhe Road
Admission: 30-40 yuan
Dancing dolphins
Dolphins jumping from the water to touch a ball, swaying their bodies to music, kissing people and doing math by tapping their tails have made the dolphinarium(海豚馆) in Peace Park an attraction for children.Seals and sea lions also perform.
Hours: 10:30 am, 4:00 pm, and 7:30 pm
Admission: 20 yuan for adults and 10 yuan for children.(252 words)If you go to visit the Long March exhibition with an Australian, how much will you pay altogether for the admission?
A.16 yuan. | B.30 yuan. | C.23 yuan. | D.20 yuan. |
Which of the following is NOT done by the Thai elephants?
A.Riding bicycles. |
B.Blowing a mouth-organ. |
C.Having a tug-of-war with people. |
D.Doing math. |
The dolphinarium in Peace Park is a hall where you can see ______.
A.only seals and sea lions perform |
B.only dolphins perform |
C.not only dolphins but also seals and sea lions perform |
D.only seals perform |
Eyesight problems are common among all ages and if they are left untreated, they can cause serious headaches or other problems. The good news is that most eyesight problems can easily be sorted out by wearing glasses.
Regular eye tests are important for everyone. Children and teenagers, under the age of 16 and up to the age of 19 for those full-time education, have the right to have eye tests for free in Britain. As the eye test is free, there’s no excuse for not having a regular eye test. Doctors suggest that it’s better to have an eye test about once a year.
Wearing glasses isnt always regarded as all that cool and teens who suddenly need to wear glasses may find it difficult to accept. If theyve grown up wearing glasses, then they may be more used to it. However, if your eyes are in poor health, not wearing glasses can put even more pressure on your eyes and could make them even worse.
Thankfully, the days of little choice of glasses frames (框架) for teenagers are gone and there’s now a wide selection of frames. If a teen does need to wear glasses, then it’s good to let him or her choose the type, as he or she will be able to choose something he or she feels comfortable. Dont forget to be guided by the experts on glasses too.According to the text, teens in the UK ______.
A.have few eyesight problems |
B.can design their own glasses |
C.change their glasses very often |
D.can check their eyes without paying |
How often do doctors suggest teens to have an eye test?
A.Once a month. |
B.Once every six months. |
C.Once a year. |
D.Twice a year. |
It can be learned from the text that teens ______.
A.find it difficult to buy comfortable glasses |
B.prefer to wear cool glasses at an early age |
C.are advised to wear glasses if their eyesight is poor |
D.think they are much cooler when wearing glasses |
In the past, teens who wanted to buy glasses ______.
A.were unable to find the right glasses |
B.only had a few styles to choose from |
C.could not find an expert to ask for advice |
D.were worried about the quality of glasses |
When Xia Min started drinking alcohol(酒精,乙醇) with her classmates at a friend’s birthday, she didn’t realize what would happen to her. She drank a lot and fell into a coma (昏迷). The 15year-old girl from Chongqing never recovered.
Xia’s death is warning to other students. A new rule went into effect on January 1, 2006. Teens are not allowed to buy or drink alcohol. Shops are not allowed to sell it to them.
A 1999 Chinese law forbade (禁止) shops to sell alcohol to youths under 18. But it is not taken seriously by shopkeepers because it doesn’t have specific rules. People hope the new rule will work.
“I tasted alcohol when having the dinner of the last New Year’s Eve,” said Lian Yuqi, a 16-year-old girl in Xiamen. She believes that the new rule will stop teens from drinking and help them grow in a healthy way.
“Although it may be a little disappointing not to have beer at parties, I think we can have soft drinks instead,” she said.Xia Min died from alcohol at the age of ______.
A.15 | B.16 | C.17 | D.18 |
The underlined word it means ________.
A.a warning sing | B.a shopkeeper |
C.the new rule | D.a 1999 Chinese law |
We can know that ________.
A.it is against the new rule for youths under 18 to drink alcohol |
B.shops can sell alcohol to a 16 years old youth. |
C.without an ID card, young people cant buy alcohol |
D.it seems that the young girl, Liang Yuqi, likes to drink alcohol |
According to the passage, which of the following is TRUE?
A.The new rule has worked very well. |
B.Shopkeepers can sell alcohol to teens above 18. |
C.Chinas legal drinking age is clearly under18. |
D.Many teens drink alcohol to show theyve grown up. |
If your mother wants to tell you something , she uses words . Birds can not talk as we do . But some birds can make sounds to warn their young of danger . They have their own ways to make the young birds do certain thing .
The jackdaw is a kind of blackbirds that lives in Europe . Jackdaws live together in flocks. (群) Yong jackdaws do not know their enemies . When an older jackdaw sees a dog , it makes a loud tattling (格格响的)sound. The young birds know this sound means an enemy is nearby. The sounds warns them to know their enemy .
If a young jackdaw is in a dangerous place, a jackdaw parent flies over him from behind .The parent bird flies low over the young birds back, the parents’ tail feathers move quickly from side to side, It is trying to say , “ Follow me .”
At the same time , the parent calls out , “ Key-aw ,Key-aw .” The parent means , “ Fly home with me .” The young bird then follows the older one home .
Young jackdaws do not have to learn what certain sounds mean. They know the meaning of these sounds from the time they hatch (孵化,小鸡等出壳).The jackdaw lives in _____ .
A.Europe | B.Australia |
C.America | D.Africa |
When an old jackdaw sees a dog , it _____ .
A.calls out “Follow me .” |
B.makes a loud sound |
C.flies away |
D.fights the dog . |
Parent jackdaw can use their tail feathers to ______ .
A.ask their young to follow them |
B.play a game with the young |
C.tell the meal time |
D.give a warning of a fire |
Which of the following does this story lead you to believe ?
A.All animal parents can talk to their young. |
B.Dogs are the most dangerous enemies for jackdaws. |
C.Young jackdaws know the meaning of their parents sound when they grow older. |
D.Some birds can give certain information to one another. |
New research shows that the healthy brain may hold memories which we don’t even remember. In The Journal of Neuroscience, experts report that the brain might hold more memories than people realize, but that restoring those memories can be tricky.
Memory Check
First, participants saw a list of 120 real words mixed with 80 nonsense words. Next, they saw another word list and tried to remember which words had been on the first list. Meanwhile, their brains were scanned with functional magnetic resonance(核磁共振) imaging.
While participants reviewed the second word list, their brain scans showed more activity in a certain brain area -- the posterior(后部的) median temporal lobe(脑叶) -- when they saw words that had been on the first word list.
But participants didn’t always remember that they’d seen those words before. Sometimes, they goofed and said they hadn’t seen those words before. In other words, the posterior median temporal lobe was more sensitive to memory than participants’ consciousness, the researchers note.
“Album”of Memories
Another part of the median temporal lobe also attracted the scientists’ attention. The anterior(前面的)median temporal lobe showed more activity when participants thought they were seeing a new word, the study shows.
So, why did participants sometimes mess up their memory recall? It might be that two parts of their brain -- the posterior and anterior median temporal lobes -- might be dueling(决斗) for the upper hand in deciding what actually happened in the past, the study notes.
In other words, memories might have a photo album in the brain, but sometimes we forget what’s on all of the photo album’s pages.A person sometimes has difficulty recalling because.
A.he is unconscious when he gets his memories |
B.he forgets what is on the pages of the photo album |
C.there are two parts in his brain dueling for the upper advantage |
D.the anterior median temporal lobe is more active than the posterior |
According to the passage the researchers are.
A.studying how a person remembers things |
B.studying a magazine The Journal of Neuroscience |
C.examining posterior and anterior median temporal lobes |
D.doing experiments to find out what disturbs a person’s memory |
What did the experts discover when the participants saw the words on the first word list appear on the second word list?
A.The instrument worked faster. |
B.The participants were more conscious. |
C.The posterior median temporal lobe was more active. |
D.The anterior median temporal lobe was more active. |
The underlined wordgoofedin the fourth paragraph means.
A.made a mess of | B.made an answer for |
C.made out of | D.made the best of |