Batteries can power anything from small sensors to large systems.While scientist

Batteries can power anything from small sensors to large systems.While scientist

题型:不详难度:来源:
Batteries can power anything from small sensors to large systems.While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves.University of Missouri(MU) researchers are developing a nuclear energy source that is smaller, lighter and more efficient.
“To provide enough power, we need certain methods with high energy density(密度)”,said Jae Kwon, assistant professor of electrical and computer engineering at MU.“The radioisotope(放射性同位素) battery can provide power density that is much higher than chemical batteries.”
Kwon and his research team have been working on building a small nuclear battery, presently the size and thickness of a penny, intended to power various micro / nanoelectromechanical systems (M/NEMS).Although nuclear batteries can cause concerns, Kwon said they are safe.
“People hear the word ‘nuclear’ and think of something very dangerous,” he said, “However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”
His new idea is not only in the battery’s size, but also in its semiconductor(半导体).Kwon’s battery uses a liquid semiconductor rather than a solid semiconductor.
“The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure(晶体结构) of the solid semiconductor,” Kwon said, “By using a liquid semiconductor, we believe we can minimize that problem.”
Together with J.David Robertson, chemistry professor and associate director of the MU Research Reactor, Kwon is working to build and test the battery.In the future, they hope to increase the battery’s power, shrink its size and try with various other materials.Kwon said that battery could be thinner than the thickness of human hair.
小题1:Jae Kwon gave examples in Paragraph 4_________.
A.to show chemical batteries are widely applied.
B.to introduce nuclear batteries can be safely used.
C.to describe a nuclear-powered system.
D.to introduce various energy sources.
小题2:According to Jae Kwon, his nuclear battery _______.
A.uses a solid semiconductorB.will soon replace the present ones.
C.could be extremely thinD.has passed the final test.
小题3:The text is most probably a ________.
A.science news reportB.book review
C.newspaper adD.science fiction

答案

小题1:B
小题2:C
小题3:A
解析

试题分析:本文介绍了新型的核技术的电池的发展,这种电池体积更小,能量更大。
小题1:B 推理题。根据本段nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”说明现在的技术已经很完美,安全性能也很高,说明主语的电池可以被安全地使用,故B正确。
小题2:C 细节题。根据文章最后一句Kwon said that battery could be thinner than the thickness of human hair.说明这样的电池可能会非常thin。故C项正确。
小题3:A 推理题。本文是关于新型的电池的研究,其中涉及到高科技的核技术,那么最有可能是从科技报告中取出来的,故A正确。
点评:文中涉及的是核技术运用于电池方面的信息。属于科普类短文,此类文章的最大的障碍是词汇以及考生对阅读内容的不熟悉,需要考生在阅读的时候有足够的耐心。要养成在上下文串联中猜测词义的能力,根据上下文中出现的同义词,近义词,反义词,以及词义的解释来理解生词。同时要抓住文章的中心,不要受其他信息的影响。要根据题目及选项以及文章的上下文串联合理的判断推理。
举一反三
Surgeons in Spain have successfully carried out the world’s first organ transplant using new stem cell technology. Some people are calling it the greatest medical breakthrough so far this century.
But what are stem cells? As we know, most cells in our bodies are designed to serve specific purposes – for example, a liver cell develops to work in the liver and cannot become a heart cell. But stem cells are different. They are very young, and in the laboratory scientists can grow them into different types of cell.
Claudia Castillo needed a new windpipe after getting a serious disease. Scientists from the University of Bristol in the UK took a donor windpipe, or trachea, from someone who had recently died. They used strong chemicals to remove the donor’s cells, leaving a tissue scaffold(组织支架). This was refilled with cells from Ms Castillo’s windpipe, and stem cells from her bone. After four days the cells had grown sufficiently for the windpipe to be transplanted into Ms Castillo.
Currently, transplant patients have to take drugs for the rest of their lives to prevent their bodies rejecting the new organs. These drugs can have bad side-effects, and do not always prevent rejection. But by using Ms Castillo’s own cells, doctors were able to trick her body into thinking the new windpipe was her own organ. Five months on, Claudia Castillo is in perfect health.
This ground-breaking procedure could be used in other transplant operations in the future. Scientists also believe stem cells might be used to treat Parkinson"s disease, Alzheimer"s disease, heart disease, stroke, arthritis, diabetes, burns and so on.
However, stem cell research is extremely controversial. The most effective stem cells do not come from adults but from embryos created in laboratories and which are just a few days old. Many people have religious or ethical objections to growing embryos, even if they can be used to cure diseases.
小题1:This transplant is considered the greatest medical breakthrough because _________.
A.this is the first organ transplant in the whole world
B.the patient is in perfect health after the operation
C.it is the first success with new stem cell technology
D.the stem cells are from an embryo developed in a lab
小题2:Stem cells are different from the other ceils in the way that __________.
A.they are grown in the lab only
B.they can grow into different types of cell
C.they are designed for a specific purpose
D.they can work in the liver not in the heart
小题3:What is the main idea of the third paragraph?
A.How Claudia survived in the operation
B.How to remove the cells from the donor’s organ
C.Why stem cells are needed in the transplant
D.How the windpipe is transplanted
小题4:Which of the following is TRUE according to the passage?
A.Human bodies always reject transplanted organs even with their own cells
B.The donor’s cells had to be removed because they were unhealthy
C.The transplanted organ was refilled with the stem cells only
D.Claudia will not have to take drugs to prevent rejection.
小题5:Which word can best describe the scientists’ attitude towards the stem cell technology?
A.controversialB.confident
C.conservative (保守的)D.critical

题型:不详难度:| 查看答案
Tuesday the twelfth was my birthday. I  16 a day of cake and presents  17__     it turned into a day of mystery(神秘). Someone sent a bottle with a letter and a treasure map   18 . It said there was a treasure of over 20 million dollars. I didn’t know if it was a trick(恶作剧) or if I should   19  it. If it was   20  , it would be the best present I had ever got. I decided to  21 . Two of my friends came and we rented a truck.   22 , I thought about turning back twice during this trip, but I didn’t think it was a 23 decision for me to make. I   24 to give this trip twice the effort(努力) I had been putting in. This would take all my trust in order for me to find the  25  .
“The map says you have to turn when you see a large stone with a red circle,” said one of them.
“What do we do after the turn?” I asked   26 .
“It says we should see a tree. We are   27  to turn 20 meters north of it and dig. 
We got there and dug. We had   28  at first digging but we got better and worked very   29 . My trousers were dirty but I kept digging   30  I hit something. It was a large metal box. We   31  the lock and looked inside. There was a letter. It read:
  “The lesson you have learned will be very   32  . If you put as much   33 in anything you do as you did in finding the   34  , you will have found the key to making over 20 million dollars.”
  This was a trick from my parents. I thought I would never forget this   35    birthday present.
小题1:
A.expectedB.acceptedC.passedD.planned
小题2:
A.orB.butC.andD.so
小题3:
A.aboveB.awayC.insideD.nearby
小题4:
A.trustB.forgetC.refuseD.share
小题5:
A.commonB.easyC.interestingD.real
小题6:
A.chooseB.tryC.askD.think
小题7:
A.LuckilyB.FinallyC.ProbablyD.Actually
小题8:
A.wiseB.bigC.differentD.quick
小题9:
A.hatedB.failedC.neededD.remembered
小题10:
A.pleasureB.truthC.helpD.aim
小题11:
A.gratefullyB.sadlyC.angrilyD.seriously
小题12:
A.allowedB.requiredC.forcedD.encouraged
小题13:
A.trainingB.experienceC.troubleD.fun
小题14:
A.quicklyB.badlyC.tiredlyD.carefully
小题15:
A.sinceB.ifC.becauseD.until
小题16:
A.repairedB.openedC.changedD.cleaned
小题17:
A.valuableB.necessaryC.satisfyingD.painful
小题18:
A.timeB.moneyC.healthD.energy
小题19:
A.bottleB.mapC.letterD.tree
小题20:
A.prettyB.perfectC.specialD.expensive

题型:不详难度:| 查看答案
It is easier to float in the ocean than it is to float in a swimming pool. Do you know why?
Ocean water is full of salt— and salt water can hold up more weigh than fresh water. See for yourself!
You Will Need:
● 3 cups of warm water
● Measuring cup (量杯)
● Wide-mouthed jar
● Salt
● Spoon
● Raw (生的)potato
You Will Do:
1. Pour 1.5 cups of warm water into the jar.
2. Add 1/3 cup of salt.
3. Stir(搅拌) until the salt is completely dissolved.
4. Add another 1.5 cups of water. Pour it slowly over the back of the spoon into the jar so that the two liquid will not mix together.
5. Gently place the potato into the jar. Do not drop it.
What Will Happen:
The potato will sink— but only halfway!
Why?
Salt water is heavier than fresh water, so it will stay on the bottom. The fresh water will remain on top.
The potato is heavier than the fresh water, but it is lighter than the salt water. That is why the potato will sink halfway down.
小题1:In the experiment, what should you do right after you pour the water over the spoon?
A.Add the salt to the water.B.Stir the salt into the water.
C.Place the potato in the jar.D.Pour warm water into thejar.
小题2:In Step 4 of the experiment, why do you pour the water over the spoon “slowly”?
A.It is easier to see what you are doing.
B.It pushes the fresh water to the bottom.
C.It will keep the water from coming out.
D.It will keep the liquids from mixing together.
小题3:In which step of the experiment do you add the salt?
A.Step 1B.Step 2C.Step 3D.Step 4
小题4:What does the underlined word “gently” mean?
A.CarefullyB.QuicklyC.SecretlyD.Silently

题型:不详难度:| 查看答案
Researchers at San Diego Zoo have been studying what has been described as the “secret language” of elephants. They have been monitoring(监测) communications between animals that cannot be heard by human ears.
The elephant’s call will be familiar to most people, but the animals also give out growls (低吼). Their growls, however, are only partly audible (听得见的); two-thirds of the call is at frequencies that are too low to be picked up by our hearing. To learn more about the inaudible part of the growl, the team attached (附在……上面) a microphone sensitive to these low frequencies and a GPS tracking system to eight of the zoo’s female elephants. The researchers could then relate the noises the animals were making to what they were doing. Matt Anderson, who led the project, told BBC News, “We’re excited to learn how they interact and contact with one another.”
The team has already learned that pregnant females use this low frequency communication to announce to the rest of their long gestation (妊娠期) of over two years, in the last 12 days we see the low part of the growl, which we can’t hear. This we believe is to announce to the rest of the herd that the baby is upcoming,” said Dr Anderson.
The researchers believe that this also warns the elephants to look out for coming danger. “You may think that a baby calf of about 300 pounds would not be as open to predation (捕食) as other species,” he says. “But packs of hyenas (袋狼) are a big threat in the wild.”
Female elephants are only in season for around four days every four years and these calls can be heard by males more than two miles away.
小题1:Why some elephants’ call is called “secret language”?
A.Because it can’t be heard by human ears.
B.Because it can only be heard by female elephants.
C.Because people don’t know its meanings.
D.Because people haven’t studied it completely.
小题2:By using a sensitive microphone and a GPS tracking system, the researchers wanted to find out             .
A.where the elephants usually go
B.what the elephants’ growls really mean
C.how mother elephants raise baby calves
D.how elephants protect their babies.
小题3:A pregnant elephant uses inaudible growls to           .
A.show the location where she is staying
B.ask for help when she losses her way
C.scare away the enemy
D.let others know she will have a baby
小题4:What is the passage mainly about?
A.The elephants can speak like people.
B.The wild elephants’ ways to fight against enemies.
C.The “secret language” between elephants.
D.The special life of female elephants.

题型:不详难度:| 查看答案
___1____ Maybe you thought that they were just happy. After all, you probably sing or whistle when you are happy.
However, they sing most of the time for a very different reason. ____2___ Some scientists believe that birds do sing some of the time just because they are happy.
Do you know what a “territory” is? A territory is an area that an animal, usually the male, claims(声称)as its own. ____3___ No other families of the same species are welcome. Your yard and house are your territory where only your family and friends are welcome. If a stranger should enter your territory and threaten you, you might shout. Probably this would be enough to frighten him away. If so, you have actually scared the stranger away without having to fight him. A bird does the same thing. But he expects an outsider almost any time, especially at nesting(筑巢)season. So he is screaming all the time, whether he can see an outsider or not.__4__.
Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs. You can see that birds have a language all their own. ___5__
A.Only he and his family are welcome there.
B.Most of it has to do with attracting mates and setting up territories.
C.Have you ever wondered why birds sing?
D.Their singing is actually a warning to other birds to stay out of their territory.
E. Have you ever wondered why birds sing?
F. Most of the language is widely used.
G. This screaming is what we call a bird’s song, and it is usually enough to keep an outsider away.
题型:不详难度:| 查看答案
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