Scientists have found what look like caves on Mars(火星), and say they could be protecting life from the planet’s terrible environment.
The first caves discovered beyond the Earth appear as seven mysterious black dots on the pictures sent back by NASA’s Mars Odyssey orbiter. Each as large as a football field, they may be openings into natural caves below the Martian surface.
“If there is life on Mars, there is a good chance you’d find it in caves,” said Jut Wynne, one of the researchers who noticed the features while working on a US Geological Survey Mars Cave Detection Program.
Jonathan Clarke, a geologist with the Mars Society of Australia, yesterday described the discovery as exciting.
One photo taken at night by an infrared imager(紅外線成像器) showed one hole to be unusually warm, suggesting hot air trapped during the day is flowing out.
“I said: ‘Wow, that’s a cave’” Dr. Clarke said excitedly. “People have been looking for these for a long time; now we have found them.”
He agreed such caves would be perfect places to hunt for life escaping from the bitterly cold, radiation-soaked(充滿輻射的), dry surface.
“Tiny drops of water could collect inside,” he said. “If there are gases coming out, they could provide energy for a whole range of bacteria. A cave is also a protection from radiation; the surface of Mars is exposed to high levels of space radiation.”
The caves probably formed when tube-shaped lave flows(管狀巖漿流) spread across the planet long ago. The outside of the tubes cooled, forming solid walls, while something hotter inside allowed the remaining have to flow out, forming caves. 
小題1:What does the passage mainly talk about?
A.How the caves were formed on Mars.B.How scientists found these caves on Mars.
C.Caves on Mars may be full of hot air or a sign of life.
D.Scientists have completely recognized the surface of Mars.
小題2:We can learn from the passage that           .
A.water has already been found on MarsB.the scientists found all the caves at night
C.it is certain that there is life in these caves
D.the surface of Mars is bitterly cold, radiation-soaked and dry
小題3:According to the passage, Dr. Clarke was so excited because        .
A.such caves could provide energy for lifeB.they had finally found the caves on Mars
C.such caves would be perfect places to hunt for life
D.scientists had long been looking for these caves
小題4:Necessary conditions for life on Mars mentioned in the passage may include        .
A.lava and energyB.water and radiation from space
C.gases and lavaD.water and protection from radiation

小題1:C
小題2:D
小題3:B
小題4:D

小題1:這是一道主旨題。本文主要介紹了科學家在火星上發(fā)現(xiàn)一些坑洞,這些坑洞可以聚集熱空氣和水分,使生命出現(xiàn)變得可能。本文也描述了這些坑洞發(fā)現(xiàn)的過程和形成原因,但都不是主要描述的內容,所以A項和B項不全面。
小題2:這是一道判斷題。根據(jù)倒數(shù)第三段“He agreed such caves would be perfect places to hunt for life escaping from the bitterly cold, radiation-soaked, dry surface.”可以判斷出火星表面是個極端寒冷、充滿輻射、干燥的地方。A、C選項都是文中的推測,并沒有得出明確的結論。
小題3:這是一道推斷題。根據(jù)第六段Dr.Clarke的表述“People have been looking for these for a long time;now we have found them.”可知Clarke教授的喜悅是因為人們找這些坑洞很長時間了,現(xiàn)在終于找到了。
小題4:這是一道歸納題。根據(jù)坑洞中可能出現(xiàn)生命以及倒數(shù)第二段“Tiny drops of water could collect inside,”和“A cave is also a protection from radiation”可以歸納出生命產生需要水和避免輻射。
練習冊系列答案
相關習題

科目:高中英語 來源:不詳 題型:閱讀理解

With the start of the new semester students around the country exchange their fun and fashionable clothes for boring school uniforms.
"The uniform makes us look like a bunch of clones, especially when we are doing morning exercises in the playground, "said Qing, a Senior 2 from a high school in Shanghai. "But we are not exactly the same from the top to the bottom. The boys wear different sport shoes and girls have different decorations ( 裝飾品 )in their hair. These are the areas where you can express yourself" said Qing.
Although it might be strange for boys to talk about fashion, they do care about what they wear in school, especially shoes, according to Qing.
"Nike and Adidas basketball shoes, although they are still the must for many of my friends ,are becoming out-of-date,” added. He explained, "Since Liu Xiang ran so fast in Athens, running shoes are becoming popular in this autumn."
"Still in fashion are the various baseball caps and American-style T-shirts with random English words printed on them, "said Qing. "The accuracy ( 準確性 )of the written message isn't important. Often, the words are misspelt . Sometimes they do not even make sense “ Qing said with a smile.
Besides sports shoes and T-shirts, styles and colours of school bags are another opportunity for students to express their taste in fashion. Some bags are made more eye-catching by decorating them with small hanging dolls. Other fashionable items are the colourful drink contains which are now popular among girls this semester.
As in China, the new semester in the US also brings new fashion trends: shirts printed with Chinese words, necklaces with Hebrew ( 希伯萊 )or Hindi ( 印度的 )characters, and Brazilian jewelry, are all common in schools in Florida, according to Carmen Domingues, a high school student.
小題1:What does "a bunch of  clones”( Paragraph 2)mean?
A.All of the clothes are the same.B.All of the exercises are the same.
C.All of the clothes are different.D.All of the exercises are different.
小題2:How do the students express themselves in school?
A.The girls wear different sport shoes.
B.All the students wear school uniforms.
C.The girls have different decorations in their hair.
D.The boys drink water from colourful drinks containers.
小題3:Why are Nike and Adidas basketball shoes becoming out-of-date?
A.Because the shoes are not eye-catching.
B.Because running shoes become more popular.
C.Because the shoes have been popular for a long time.
D.Because they have changed their opinions for Liu Xiang.
小題4:Which of the following is NOT the new fashion trends in the US?
A.Necklace with Hebrew or Hindi characters.
B.Baseball caps and American-style T-shirts.
C.Shirts printed with Chinese words.
D.Brazilian jewelry.

查看答案和解析>>

科目:高中英語 來源:不詳 題型:完形填空

For many people today, reading is no longer relaxation. To keep up their work they must read letters, reports, trade publications, interoffice communications, not to mention newspapers and magazines: a never-ending flood of words. In  1  a job or advancing in one, the ability to read and comprehend  2   can mean the difference between success and failure. Yet the unfortunate fact is that most of us are   3   readers. Most of us develop poor reading  4    at an early age, and never get over them. The main deficiency   5  in the actual stuff of language itself ——words. Taken individually, words have  6   meaning until they are strung together into phrases, sentences and paragraphs.    7  , however, the untrained reader does not read groups of words. He laboriously reads one word at a time, often regressing(退回) to  8    words or passages. Regression, the tendency to look back over   9  you have just read, is a common bad habit in reading. Another habit which  10   down the speed of reading is vocalization—sounding each word either orally or mentally as  11    reads.
  To overcome these bad habits, some reading clinics use a device called an  12  , which moves a bar (or curtain) down the page at a predetermined(預先確定的) speeD.The bar is set at a slightly faster rate  13   the reader finds comfortable, in order to “stretch” him. The accelerator forces the reader to read fast,    14  word-by-word reading, regression and subvocalization(默讀)practically impossible. At first  15  is sacrificed for speeD.But when you learn to read ideas and concepts, you will not only read faster,   16    your comprehension will improve. Many people have found  17   reading skill drastically improved after some training. 18  Charlce Au, a business manager, for instance, his reading rate was a reasonably good 172 words a minute  19   the training, now it is an excellent 1,28 words a minute. He is delighted that how he can   20  a lot more reading material in a short period of time.  
1.  A.applying B.doing       C.offering   D.getting
2.  A.quickly    B.easily       C.roughly    D.decidedly
3.  A.good       B.curious    C.poor        D.urgent
4.  A.training   B.habits      C.situations        D.custom
5.  A.lies   B.combines        C.touches    D.involves
6.  A.some       B.a lot        C.little        D.dull
7.  A.Fortunately     B.In fact      C.Logically        D.Unfortunately
8.  A.reuse       B.reread      C.rewrite     D.recite
9.  A.what        B.which      C.that D.if
10.A.scales      B.cuts C.slows       D.measures
11.A.some one        B.one   C.he    D.reader
12.A.accelerator      B.actor        C.amplifier D.observer
13.A.then        B.as     C.beyond    D.than
14.A.enabling B.leading    C.making    D.indicating
15.A.meaning B.comprehensionC.gist    D.regression
16.A.but   B.nor   C.or     D.for
17.A.our   B.your        C.their        D.such a
18.A.Look at    B.Take        C.Make       D.Consider
19.A.for   B.in     C.after        D.before
20.A.master     B.go over     C.present     D.get through

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

We do not know exactly how many whales there are in the sea because we can’t count them. But we believe at the beginning of the eighteenth century there were 105,000 humpback whales and 120,000 right whales. At the beginning of the twentieth century there were 75,000 humpbacks and 80,000 rights.
Since 1900 their numbers have fallen very quickly. Between 1935 and 1950 the number of humpbacks fell from 20,000 to 10,000 and since 1950 the number has fallen to only 6,000. The number of right whales has fallen even faster. In 1935 there were 25,000. The number fell to 6,000 in 1950 and since 1950 the number has fallen to 4,000. Men have always been hunters. Thousands of whales have become victims(犧牲品). It’s time to do something to protect whales.
小題1:Which of the following is true?
A.We know the exact number of whales in the sea.
B.It’s easy for us to count whales in the sea.
C.We find it impossible to count whales in the sea.
D.We don’t want to know how many whales there are in the sea.
小題2:The number of right whales has fallen _______.
A.more slowly than that of humpback whales
B.faster than that of humpback whales
C.as slowly as that of humpback whales
D.as fast as that of humpback whales
小題3:The passage is mainly about _______.
A.the number of humpback whales
B.the number of right whales
C.hunting whales
D.the necessity of protecting whales

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

Our “Mommy and Me” time began two years ago. My next-door neighbor and fellow mother, Christie, and I were out in our front yards, watching seven children of age 6 and under ride their bikes up and down. “I wish I could take one of my children out alone,” said Christie.
Then we worked out a plan: When Christie takes one of her children out, I’ll watch her other three. And when she watches two of mine, I’ll take someone out.
The children were extremely quick to accept the idea of “Mommy and Me” time. Christie’s daughter, McKenzie, went first. When she returned, the other children showered her with tons of questions. McKenzie was smiling broadly. Christie looked refreshed and happy. “She’s like a different child when there’s no one else around,” Christie shared with me quickly. With her mother all to herself, McKenzie didn’t have to make an effort to gain attention.
Just as Christie had noticed changes in McKenzie, I also discovered something different in each of my children during our alone times. For example, I am always surprised when my daughter, who is seldom close to me, holds my hand frequently. My stuttering(口吃的)son, Tom, doesn’t stutter once during our activities since he doesn’t have to struggle for a chance to speak. And the other son, Sam, who’s always a follower when around other children shines as a leader during our times together.
The “Mommy and Me” time allows us to be simply alone and away with each child ---talking, sharing, and laughing, which has been the biggest gain. Every child deserves(應得到)to be an only child at least once in a while.
小題1:What is the text mainly about?
A.The experience of the only child being with mother.
B.The advantage of spending time with one child at a time.
C.The happy life of two families.
D.The basic needs of children.
小題2: Right after McKenzie came back, the other children were _____________.
A.happy B.curious C.regretful D.friendly
小題3:What is one of the changes the author finds in her children?
A.The daughter acts like a leader. B.Sam holds her hand more often.
C.The boys become better followers. D.Tom has less difficulty in speaking.
小題4:The author seems to believe that ___________.
A.having brothers and sisters is fun B.it’s tiring to look after three children
C.every child needs parents’ full attention D.parents should watch others’ children

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

Antarctica and Environment
Antarctica has actually become a kind of space station – a unique observation post for detecting important changes in the world’s environment. Remote from major sources of pollution and the complex geological and ecological systems that prevail elsewhere, Antarctica makes possible scientific measurements that are often sharper and easier to interpret than those made in other parts of the world.
Growing numbers of scientists therefore see Antarctica as a distant-early-warning sensor, where potentially dangerous global trends may be spotted before they show up to the north. One promising field of investigation is glaciology. Scholars from the United States, Switzerland, and France are pursuing seven separate but related projects that reflect their concern for the health of the West Antarctic Ice Sheet – a concern they believe the world at large should share.
The Transantarctic Mountain, some of them more than 14,000 feet high, divide the continent into two very different regions. The part of the continent to the “east” of the mountains is a high plateau covered by an ice sheet nearly two miles thick. “West” of the mountain, the half of the continent south of the Americas is also covered by an ice sheet, but there the ice rests on rock that is mostly well below sea level. If the West Antarctic Ice Sheet disappeared, the western part of the continent would be reduced to a sparse cluster of island.
While ice and snow are obviously central to many environmental experiments, others focus on the mysterious “dry valley” of Antarctica, valleys that contain little ice or snow even in the depths of winter. Slashed through the mountains of southern Victoria Land, these valleys once held enormous glaciers that descended 9,000 feet from the polar plateau to the Ross Sea. Now the glaciers are gone, perhaps a casualty of the global warming trend during the 10,000 years since the ice age. Even the snow that falls in the dry valleys is blasted out by vicious winds that roars down from the polar plateau to the sea. Left bare are spectacular gorges, rippled fields of sand dunes, clusters of boulders sculptured into fantastic shapes by 100-mile-an-hour winds, and an aura of extraterrestrial desolation.
Despite the unearthly aspect of the dry valleys, some scientists believe they may carry a message of hope of the verdant parts of the earth. Some scientists believe that in some cases the dry valleys may soak up pollutants faster than pollutants enter them.
小題1:What is the best title for this passage?
A Antarctica and environmental Problems.
B Antarctica: Earth’s Early-Warning station.
C Antarctica: a Unique Observation Post.
D Antarctica: a Mysterious Place.
小題2:What would the result be if the West Antarctic Ice Sheet disappeared?
A The western part of the continent would be disappeared.
B The western part of the continent would be reduced.
C The western part of the continent would become scattered Islands.
D The western part of the continent would be reduced to a cluster of Islands.
小題3:Why are the Dry Valleys left bare?
A Vicious wind blasts the snow away.                B It rarely snows.
C Because of the global warming trend and fierce wind.  D Sand dunes.
小題4:Which of the following is true?
A The “Dry Valleys” have nothing left inside.
B The “Dry Valleys” never held glaciers.
C The “Dry Valleys” may carry a message of hope for the verdant.
D The “Dry Valleys” are useless to scientists.

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

 To many web-building spiders, most of whom are nearly blind, the web is their essential window on the world: their means of communicating, capturing prey(獵物), meeting mates and protecting themselves. A web-building spider without its web is like a men cast away on an island of solid rock,totally out of touch and destined to

starve to death.
So important is the web to an orb-web spider's survival that the animal will continue to construct new webs daily even if it is being starved. For 16 days the starving spider builds completely normal webs. Then, as the animal gets scrawnier(憔悴的), it constructs a wider-meshed web using fewer strands(線). Such webs would only trap larger prey, which is more economical from the perspective of a starving spider.
The spider stores energy by recycling web protein. It simply eats its own web each evening and reuses it to produce new silk. In studies with radioactively,labeled materials, it was found that 95 percent of web protein reappears in the next day' web. Most of the energy needed for web-building is used in walking over the strands as they are laid down.
Scientists are impressed by the adaptability of the spider's highly preprogrammed brain, which is larger for its size than the brain of any other invertebrate(無脊推動物).If web-building is interrupted, or if some of the existing strands are destroyed,the spider simply goes back to see where the web is left off and then finishes building a normal web. One spider will finish building the incomplete web of another. 
小題1: Which of the following best expresses the main ideas of the passage?
A.Secrets of Spiders' AdaptabilityB.Importance of Webs to Spiders
C.Secrets of the Spiders' Life D.Spiders' Highly Preprogrammed Brain
小題2:According to the passage, which of the following statements is TRUE?
A.Most spiders will stop conducting webs when hungry.
B.One Web-building spider usually conducts one web.
C.Web-building spiders will probably die without their webs.
D.Web-building spiders have good eyesight.
小題3:A spider conducts a wider-meshed web when____________.
A.it is 16 days oldB.it is getting weaker
C.it has fewer wendsD.it hunts for food
小題4:A spider's ability to finish an incomplete web proves that___________.
A.it has a highly preprogrammed brainB.it reuses its web protein to reproduce new silk
C.the web is everything for a spiderD.it is able to rebuild a destroyed web

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

Electricity, like clean water, is a resource that’s often taken for granted. But last summer, when blackouts struck much of the northeastern US, Ontario and Rome, consumers on two continents were given a painful reminder of just how easily broken electricity supplies can be. The massive disorder stranded (使陷入困境)commuters, stopped freezers, shut down businesses and refocused attention on where most of the planet’s power comes from:oil-and-gas-fired generators and nuclear plants, These sources not only pollute the environment but also make many consumers feel unacceptable health risks.
Companies are trying to offer an alternative, clean energy from renewable resources that’s plentiful and portable. Lifton’s Medis Technologies, as well as companies like Hydrogenics and Nanosys, is tapping into fuel cells and dolor panels to give people power whenever and wherever they want it, free from dependence on local grids(電網(wǎng)).
The search for alternative energy is nothing new, but the current trend of innovators is focusing on the goal of making clean and sustainable power a mainstream commodity. For example, the fuel cell, which produces electricity from the chemical reaction between oxygen and hydrogen, has been around for about 150 years, though its commercial development did not begin until the 1960s and then only as part of NASA spacecraft. Today this technology is coming down to Earth in places like Tokyo; in nine European cities, from Stockholm to Porto, each operating three hydrogen-fuel-cell buses; and in Iceland, which is trying to create the first fuel free hydrogen economy by 2030.
When hydrogen and oxygen molecules(分子)combine, the reaction produces heat and water. Fuel cells use this reaction to generate electricity. With the cell phone and gadget(小機件)market in mind, Medis has developed a fuel cell with cheap components that produces little heat and effortlessly reduces waste water without turning to energy consuming pumps.
小題1:What is the passage mainly about?
A.The future of alternative energy
B.How the fuel cells works
C.People’s search for alternative energy
D.The damage done by the blackout last summer.
小題2:What can we know about the fuel cell?
A.Its commercial use began in the 1960s.
B.Today it’s being used in almost every corner of the world.
C.It has been in widespread used for about 150 years.
D.It supplies electricity to make the combination of oxygen and hydrogen possible.
小題3:Which of the following statements is NOT true according to the passage?
A.Lifton’s Medis Technologies is tapping into fuel cells and solar panels.
B.The fuel cell has been around for about 150 years.
C.The fuel cell’s commercial development did not begin until the 1960s.
D.When hydrogen and oxygen molecules combine, the reaction produces o2 and H2O.
小題4:The underlined word “blackouts” in the 1 st paragraph means_____.
A.power failureB.the delivering of electricity
C.the power of electricityD.power station

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

With only about 1, 000 pandas left in the world, China is desperately trying to clone(克隆) the animal and save the endangered species(物種). That’s a move similar to what a Texas A & M University researchers have been undertaking for the past five years in a project called “Noah’s Ark”.
Noah’s Ark is aimed at collecting eggs, embryos(胚胎), semen and DNA of endangered animals and storing them in liquid nitrogen. If certain species should become extinct, Dr. Duane Kraemer, a professor in Texas A & M’s College of Veterinary Medicine, says there would be enough of the basic building blocks to reintroduce the species in the future.
It is estimated that as many as 2, 000 species of mammals, birds reptiles will become extinct in over 100 years. The panda, native only to China, is in danger of becoming extinct in the next 25 years.
This week, Chinese scientists said they grew an embryo by introducing cells from a dead female panda into the egg cells of a Japanese white rabbit. They are now trying to implant the embryo into a host animal.
The entire procedure could take from three to five years to complete.
“The nuclear transfer(核子移植) of one species to another is not easy, and the lack of available(capable of being used) panda eggs could be a major problem,” Kraemer believes. “They will probably have to do several hundred transfers to result in one pregnancy (having a baby). It takes a long time and it’s difficult, but this could be groundbreaking science if it works. They are certainly not putting any live pandas at risk, so it is worth the effort,” adds Kraemer, who is one of the leaders of the Project at Texas A& M, the first-ever attempt at cloning a dog.
“They are trying to do something that’s never been done, and this is very similar to our work in Noah’s Ark. We’re both trying to save animals that face extinction. I certainly appreciate their effort and there’s a lot we can learn from what they are attempting to do. It’s a research that is very much needed.”
小題1:The aim of “Noah’s Ark” project is to _______.
A.make efforts to clone the endangered pandas
B.save endangered animals from dying out
C.collect DNA of endangered animals to study
D.transfer the nuclear of one animal to another
小題2:According to Professor Kraemer, the major problem in cloning pandas would be the lack of _______.
A.available panda eggsB.host animals
C.qualified researchersD.enough money
小題3:The best title for the passage may be _______.
A.China’s Success in Pandas Cloning
B.The First Cloned Panda in the World
C.Exploring the Possibility to Clone Pandas
D.China —the Native Place of Pandas Forever
小題4:From the passage we know that _______.
A.Kraemer and his team have succeeded in cloning a dog
B.scientists try to implant a panda’s egg into a rabbit
C.Kraemer will work with Chinese scientists in clone researches
D.about two thousand of species will probably die out in a century

查看答案和解析>>

同步練習冊答案