Life in the Clear
Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between the surface of the ocean and a depth of about 3,300 feet---as far as most light can reach. Most of them are extremely delicate and can be damaged by a simple touch. Sonke Johnsen, a scientist in biology, says, “These animals live through their life alone. They never touch anything unless they’re eating it, or unless something is eating them.”
And they are as clear as glass. How does an animal become see-through? It s trickier than you might think.
The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and scatter (散射) light, bouncing it away from its original path. Others absorb light, stopping it dead in its tracks. Both scattering and absorption make an object look different from other objects around it, so you can see it easily.
But a transparent object doesn’t absorb or scatter light, at least not very much. Light can pass through it without bending or stopping. That means a transparent object doesn’t look very different from the surrounding air or water. You don’t see it you see the things behind it.
To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments (色素) that absorb specific colors of light. But a transparent animal doesn’t have pigments, so its tissues won’t absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering.
Animals are built of many different materials---skin, fat, and more---and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see-through. Others build a large, clear mass of non-living jelly-like (果冻状的) material and spread themselves over it.
Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they’re doing it is still unknown. One thing is clear: for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.
1.According to Paragraph 1,transparent animals .
A. stay in groups B. can be easily damaged
C. appear only in deep ocean D. are beautiful creatures
2.The underlined word “dead” in Paragraph 3 means .
A. silently B. gradually
C. regularly D. completely
3.One way for an animal to become transparent is to .
A. change the direction of light travel B. gather materials to scatter light
C. avoid the absorption of light D. grow bigger to stop light
4.The last paragraph tells us that larger transparent animals .
A. move more slowly in deep water
B. stay see-through even after death
C. produce more tissues for their survival
D. take effective action to reduce light spreading
The oddness of life in space never quite goes away. Here are some examples.
First consider something as simple as sleep. Its position presents its own challenges. The main question is whether you want your arms inside or outside the sleeping bag. If you leave your arms out, they float free in zero gravity, often giving a sleeping astronaut the look of a funny ballet（芭蕾）dancer. “I’m an inside guy,” Mike Hopkins says, who returned from a six-month tour on the International Space Station. “I like to be wrapped up.”
On the station, the ordinary becomes strange. The exercise bike for the American astronauts has no handlebars. It also has no seat. With no gravity, it’s just as easy to pedal violently. You can watch a movie while you pedal by floating a microcomputer anywhere you want. But station residents have to be careful about staying in one place too long. Without gravity to help circulate air, the carbon dioxide you exhale（呼气）has a tendency to form an invisible（隐形的）cloud around your head. You can end up with what astronauts call a carbon-dioxide headache.
Leroy Chiao, 54, an American retired astronaut after four flights, describes what happens even before you float out of your seat. “Your inner ear thinks you’re falling. Meanwhile your eyes are telling you you’re standing straight. That can be annoying－that’s why some people feel sick. “Within a couple of days truly terrible days for some－astronauts’ brains learn to ignore the panicky signals from the inner ear, and space sickness disappears.
Space travel can be so delightful but at the same time invisibly dangerous. For instance, astronauts lose bone mass’ That’s why exercise is considered so vital that National Aeronautics and Space Administration（NASA）puts it right on the workday schedule. The focus on fitness is as much about science and the future as it is about keeping any individual astronaut healthy. NASA is worried about two things: recovery time once astronauts return home, and, more importantly, how to maintain strength and fitness for the two and a half years or more that it would take to make a round-trip to Mars’
1.What is the major challenge to astronauts when they sleep in space?
A. Deciding on a proper sleep position.
B. Choosing a comfortable sleeping bag.
C. Seeking a way to fall asleep quickly.
D. Finding a right time to go to sleep.
2.The astronauts will suffer from a carbon-dioxide headache when .
A. they circle around on their bikes
B. they use microcomputers without a stop
C. they exercise in one place for a long time
D. they watch a movie while pedaling
3.Some astronauts feel sick on the station during the first few days because .
A. their senses stop working
B. they have to stand up straight
C. they float out of their seats unexpectedly
D. their brains receive contradictory messages
4.One of NASA’s major concerns about astronauts is .
A. how much exercise they do on the station
B. how they can remain healthy for long in space
C. whether they can recover after returning home
D. whether they are able to go back to the station
El Nifio, a Spanish term for “the Christ child”, was named by South American fisherman who noticed that the global weather pattern, which happens every two to seven years, reduced the amount of fishes caught around Christmas. El Nifio sees warm water, collected over several years in the western Pacific, flow back eastwards when winds that normally blow westwards weaken, or sometimes the other way round.
The weather effects both good and bad, are felt in many places. Rich countries gain more from powerful Nifio, on balance, than they lose. A study found that a strong Nifio in 1997 helped American’s economy grow by 15 billion, partly because of better agricultural harvest, farmers in the Midwest gained from extra rain. The total rise in agricultural in rich countries in growth than the fall in poor ones.
But in Indonesia extremely dry forests are in flames. A multi-year drought (干旱）in south-east Brazil is becoming worse. Though heavy rains brought about by El Nino may relieve the drought in California, they are likely to cause surface flooding and other disasters.
The most recent powerful Nino, in 1997-98, killed around 21,000 people and caused damage worth $36 billion around the globe. But such Ninos come with months of warning, and so much is known about how they happen that governments can prepare. According to the Overseas Development Institute (ODI), however, just 12% of disaster-relief funding in the past two decades has gone on reducing risks in advance, rather than recovery and rebuilding afterwards. This is despite evidence that a dollar spent on risk-reduction saves at least two on reconstruction.
Simple improvements to infrastructure (基础设施）can reduce the spread of disease. Better sewers (下水道）make it less likely that heavy rain is followed by an outbreak of the disease of bad stomach. Stronger bridges mean villages are less likely to be left without food and medicine after floods. According to a paper in 2011 by Mr Hsiang and co-authors, civil conflict is related to El Nino’s harmful effects—and the poorer the country, the stronger the link. Though the relationship may not be causal, helping divided communities to prepare for disasters would at least reduce the risk that those disasters are followed by killing and wounding people. Since the poorest are least likely to make up for their losses from disasters linked to El Nino, reducing their losses needs to be the priority.
1.What can we learn about El Nino in Paragraph 1?
A.It is named after a South American fisherman.
B.It takes place almost every year all over the world.
C.It forces fishermen to stop catching fish around Christmas.
D.It sees the changes of water flow direction in the ocean.
2.What may El Ninos bring about to the countries affected?
A.Agricultural harvests in rich countries fall.
B.Droughts become more harmful than floods.
C.Rich countries’ gains are greater than their losses.
D.Poor countries suffer less from droughts economically.
3.The data provided by ODI in Paragraph 4 suggest that_________.
A.more investment should go to risk reduction
B.governments of poor countries need more aid
C.victims of El Nino deserve more compensation
D.recovery and reconstruction should come first
4.What is the author’s purpose in writing the passage?
A.To introduce El Nino and its origin.
B.To explain the consequences of El Nino.
C.To show ways of fighting against El Nino.
D.To urge people to prepare for El Nino.
Chimps(黑猩猩) will cooperate in certain ways, like gathering in war parties to protect their territory. But beyond the minimum requirements as social beings, they have little instinct (本能) to help one another. Chimps in the wild seek food for themselves. Even chimp mothers regularly decline to share food with their children. Who are able from a young age to gather their own food.
In the laboratory, chimps don’t naturally share food either. If a chimp is put in a cage where he can pull in one plate of food for himself or, with no great effort, a plate that also provides food for a neighbor to the next cage, he will pull at random ---he just doesn’t care whether his neighbor gets fed or not. Chimps are truly selfish.
Human children, on the other hand are extremely corporative. From the earliest ages, they decide to help others, to share information and to participate a achieving common goals. The psychologist Michael Tomasello has studied this cooperativeness in a series of experiments with very young children. He finds that if babies aged 18 months see an worried adult with hands full trying to open a door, almost all will immediately try to help.
There are several reasons to believe that the urges to help, inform and share are not taught .but naturally possessed in young children. One is that these instincts appear at a very young age before most parents have started to train children to behave socially. Another is that the helping behaviors are not improved if the children are rewarded. A third reason is that social intelligence. Develops in children before their general cognitive（认知的）skills,at least when compared with chimps..In tests conducted by Tomtasell, the children did no better than the chimps on the physical world tests, but were considerably better at understanding the social world
The cure of what children’s minds have and chimps’ don’t in what Tomasello calls what. Part of this ability is that they can infer what others know or are thinking. But that, even very young children want to be part of a shared purpose. They actively seek to be part of a “we”, a group that intends to work toward a shared goal.
1.What can we learn from the experiment with chimps?
A. Chimps seldom care about others’ interests.
B. Chimps tend to provide food for their children.
C. Chimps like to take in their neighbors’ food.
D. Chimps naturally share food with each other.
2.Michael Tomasello’s tests on young children indicate that they____.
A. have the instinct to help others
B. know how to offer help to adults
C. know the world better than chimps
D. trust adults with their hands full
3.The passage is mainly about ____.
A. the helping behaviors of young children
B. ways to train children’s shared intentionality
C. cooperation as a distinctive human nature
D. the development of intelligence in children
A scientist working at her lab bench and a six-old baby playing with his food might seem to have little in common.After all,the scientist is engaged in serious research to uncover the very nature of the physical world,and the baby is,well, just playing…right?Perhaps,but some developmental psychologists have argued that this “play” is more like a scientific investigation than one might think.
Take a closer look at the baby playing at the table. Each time the bowl of rice is pushed over the table edge, it falls in the ground—and, in the process, it belongs out important evidence about how physical objects interact; bowls of rice do not flood in mid-sit, but require support to remain stable. It is likely that babies are not born knowing the basic fact of the universe; nor are they ever clearly taught it. Instead, babies may form an understanding of object support through repeated experiments and then build on this knowledge to learn even more about how objects interact. Though their ranges and tools differ, the baby’s investigation and the scientist’s experiment appear to share the same aim(to learn about the natural world), overall approach (gathering direct evidence from the world), and logic (are my observations what I expected?).
Some psychologists suggest that young children learn about more than just the physical world in this way—that they investigate human psychology and the rules of language using similar means. For example, it may only be through repeated experiments, evidence gathering, and finally overturning a theory, that a baby will come to accept the idea that other people can have different views and desires from what he or she has. For example, unlike the child, Mommy actually doesn’t like Dove chocolate.
Viewing childhood development as a scientific investigation throws on how children learn, but it also offers an inspiring look at science and scientists. Why do young children and scientists seem to be so much alike? Psychologists have suggested that science as an effort—the desire to explore, explain, and understand our world—is simply something that comes from our babyhood. Perhaps evolution provided human babies with curiosity and a natural drive to explain their worlds, and adult scientists simply make use of the same drive that served them as children. The same cognitive systems that make young children feel good about figuring something out may have been adopted by adult scientists. As some psychologists put it, “It is not that children are little scientists but that scientists are big children.”
1.According to some developmental psychologists, ________.
A.a baby’s play is nothing more than a game.
B.scientific research into babies; games is possible
C.the nature of babies’ play has been thoroughly investigated
D.a baby’s play is somehow similar to a scientist’s experiment
2.We learn from Paragraph 2 that ________.
A.scientists and babies seem to observe the world differently
B.scientists and babies often interact with each other
C.babies are born with the knowledge of object support
D.babies seem to collect evidence just as scientists do
3.Children may learn the rules of language by ________.
A.exploring the physical world
B.investigating human psychology
C.repeating their own experiments
D.observing their parents’ behaviors
4.What is the main idea of the last paragraph?
A.The world may be more clearly explained through children’s play.
B.Studying babies’ play may lead to a better understanding of science.
C.Children may have greater ability to figure out things than scientists.
D.One’s drive for scientific research may become stronger as he grows.
5.What is the author’s tone when he discusses the connection between scientists’ research and babies’ play?
A.Convincing. B.Confused.
C.Confidence. D.Cautious.
California Condor’s Shocking Recovery
California condors are North America’s largest birds, with wind-length of up to 3 meters. In the 1980s, electrical lines and lead poisoning(铅中毒) nearly drove them to dying out. Now, electric shock training and medical treatment are helping to rescue these big birds.
In the late 1980s, the last few condors were taken from the wild to be bred(繁殖). Since 1992, there have been multiple reintroductions to the wild, and there are now more than 150 flying over California and nearby Arizona, Utah and Baja in Mexico.
Electrical lines have been killing them off. “As they go in to rest for the night, they just don’t see the power lines,” says Bruce Rideout of San Diego Zoo. Their wings can bridge the gap between lines, resulting in electrocution(电死) if they touch two lines at once.
So scientists have come up with a shocking idea. Tall poles, placed in large training areas, teach the birds to stay clear of electrical lines by giving them a painful but undeadly electric shock. Before the training was introduced, 66% of set-freed birds died of electrocution. This has now dropped to 18%.
Lead poisonous has proved more difficult to deal with. When condors eat dead bodies of other animals containing lead, they absorb large quantities of lead. This affects their nervous systems and ability to produce baby birds, and can lead to kidney(肾) failures and death. So condors with high levels of lead are sent to Los Angeles Zoo, where they are treated with calcium EDTA, a chemical that removes lead from the blood over several days. This work is starting to pay off. The annual death rate for adult condors has dropped from 38% in 2000 to 5.4% in 2011.
Rideout’s team thinks that the California condors’ average survival time in the wild is now just under eight years. “Although these measures are not effective forever, they are vital for now,” he says. “They are truly good birds that are worth every effort we put into recovering them. ”
1.California condors attract researchers’ interest because they _________.
A. are active at night
B. had to be bred in the wild
C. are found only in California
D. almost died out in the 1980s
2.Researchers have found electrical lines are _________.
A. blocking condors’ journey home
B. big killers of California condors
C. rest places for condors at night
D. used to keep condors away
3.According to Paragraph 5, lead poisoning _________.
A. makes condors too nervous to fly
B. has little effect on condors’ kidneys
C. can hardly be gotten rid of from condors’ blood
D. makes it difficult for condors to produce baby birds
4.This passage shows that _________.
A. the average survival time of condors is satisfactory
B. Rideout’s research interest lies in electric engineering
C. the efforts to protect condors have brought good results
D. researchers have found the final answers to the problem
