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题型:阅读理解-阅读单选 难度:0.65 引用次数:95 题号:10422004

At some point in elementary school, your science teacher may explained to you that there are 365 days in a year because that's how long it takes for Earth to complete one full journey around the sun. What they might not have explained, however, is that it's not exactly 365 days—it’s actually closer to 365. 2421 days.

So, if we want our calendar year to begin right when Earth begins a new turn around the sun, we have to account for roughly an extra quarter of a day each year, or one day every four years. History.com reports that the Egyptians had already been doing this for a while before Europe finally caught on in 46 BC, when Roman Emperor Julius Caesar and astronomer Sosigenes put their heads together to come up with what we now call the Julian calendar, which includes 12 months, 365 days, and an additional ''leap day'' every four years on February 29.

But rounding 0.2421 up to 0.25 each year created an issue, because it didn't quite add up to a full day every four years—and that tiny difference meant that after 128 years, the calendar year ended up starting a day before Earth had completed its journey around the sun. By the 14th century, the calendar year was starting 10 days before Earth finished its orbit.

In 1582, Pope Gregory XIII sought to correct the error by suggesting that we simply skip a leap day every so often. His Gregorian calendar, which we still use today, rules that we skip the leap day during years which can be evenly divided (被整除) by 100 but not by 400. For instance, the year 2000 included a leap day because it can be divided by 100 and 400; the year 2100, on the other hand, will not include a leap day, since it's evenly divided by 100, but not by 400.

Gregory XIII’s correction to Caesar's overcorrection is itself a bit of an under-correction, so we'll probably need to reevaluate our leap day design again in about 10,000 years.

1. What do the underlined words ''put their heads together'' in paragraph 2 mean?
A.Come across each other.B.Bump their heads together.
C.Compete against each other.D.Combine their efforts.
2. According to Gregorian calendar, which year may include a leap day?
A.2100.B.1600.
C.1800.D.2020.
3. What can we learn from the passage?
A.Emperor Julius Caesar was also an astronomer.
B.Today's calendar exactly agrees with the sun's turning.
C.The 10-day early start in calendar will always exist.
D.The Gregorian calendar is not yet the most accurate.
4. What's the purpose of this passage?
A.To point out a mistake made by your science teacher.
B.To explain how long Earth makes a trip around the sun.
C.To explain in detail why the leap day is needed.
D.To explain the reason why we need a calendar.

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【推荐1】For more than twenty years scientists have been searching for signs of life on other planets. Most of these searches have been done over the radio, a scanning of the electromagnetic waves(电磁波)that come to us from outer space. The hope is that someone out there may be trying to contact us. Scientists also have sent radio and television messages, as well as messages on spacecraft traveling through space, on the chance that someone may be receptive to(准备接受的)such messages.

The most extensive search for intelligence planned so far involves using powerful radio telescopes to listen to signals from about 1,000 stars, all within 100 light years’ of Earth. In addition, astronomers will scan the entire sky to “listen” for radio messages from more distant stars. Using a computer, astronomers will be able to monitor more than eight million channels at one time. Scientists are looking for any signal that stands out from the background noise, such as a long, loud pulse or a strong tone that could have traveled great distances.

What are the chances that other intelligence life exists in our galaxy(星系)? Of the 200 billion stars in the Milky Way galaxy, scientists estimate that five percent-ten billion stars-are like our sun. They are medium size stars, probably with planets. Of these solar systems, perhaps half of them-five billion-have a planet like Earth. Such a planet would be a reasonable distance from the star for temperatures to be right for the evolution of life. Based on the estimate of five billion inhabitable (适合居住的) planets in our galaxy, most scientists agree that chances are likely that one or more of these planets support some life.

However, many scientists wonder whether intelligent life-organisms who can communicate with us-exists on other planets. Some believe that twenty years of searching with no hint (暗示) of an intelligible message indicates that no one is out there. They say that the evolution of intelligence comparable to ours is unlikely, and perhaps not even advantageous for most creatures in most environments. Insects, perhaps the most evolutionarily successful of all organisms on Earth, for instance, could not communicate over radio waves.

Other scientists believe that our search has been neither long enough nor extensive enough to rule out(排除)the possibility that intelligent life exists in our galaxy. Although our solar system is only about five billion years old, our galaxy is about 20 billion years old. Some scientists think it is likely that civilizations, in that time, much more advanced than ours have developed. Perhaps these civilizations are sending us no signals; perhaps we have not recognized the signals they have sent us. If we hope to find intelligent life, these scientists believe that we have to keep looking.

1. According to the passage, ______planets in our galaxy might be inhabitable.
A.5 billionB.10 billion
C.200 billionD.all
2. The first paragraph in this passage is mainly about _____.
A.spacecraft travelling
B.electromagnetic waves
C.why scientists are looking for signs of life on other planets
D.how scientists are looking for signs of life on other planets
3. Which of these statements is true based on the information in the passage?
A.Most scientists believe that there is intelligent life on other planets.
B.Scientists are trying different ways to find signs of life on other planets.
C.The Earth is one of the oldest planets in our galaxy.
D.We are alone in the universe.
4. What can we infer from the last paragraph?
A.If the research continues, we may find intelligent life.
B.We have been working long enough to find intelligent life.
C.Those civilizations have sent us some signals.
D.Our solar system is old enough.
2020-08-23更新 | 19次组卷
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【推荐2】The plan: turn Mars into a blue world with streams and green fields,and then fill it with creatures from the Earth. This idea may sound like something from a science fiction, but it is actually being taken seriously by many researchers. This suggests the future for the “red planet” will be the main topic for discussion at an international conference hosted by NASA this Week. Leading researchers as well as science fiction writers will attend the event. It comes as NASA is preparing a multi-billion-dollar Mars research programme.

“Turning Mars into a little earth has long been a topic in science fiction,” said Dr Michael Mever NASAs senior scientist. “Now with scientists exploring the reality we can ask what the real possibilities of changing Mars.” Most scientists agree that Mars could be turned into a little earth, although much time and money would be needed to achieve this goal. But many experts are shocked by the idea. “We are destroying our own world at an unbelievable speed and now we are talking about ruining another planet,” said Paul Murdin from the Institute of Astronomy, Cambridge, UK.

Over the past months, scientists have become increasingly confident they will find Martian life forms. Europe and Americas robot explorers have found the proof that water, mixed with soil, exists in large amounts on the planet.

In addition, two different groups of scientists announced on March 28 that they had found signs of methane (甲烷) in the Martian atmosphere: the gas is a waste product of living creatures and could be produced by microbes (微生物) living in the red planets soil. But scientists such as Dr. Lisa Pratt, a biologist at Indiana University, say that these microbes will be put in danger by the little earth project.

“Before we have even discovered if there is life on Mars, we are talking about carrying out projects that would destroy all these native life forms, all the strange microbes that we hope to find buried in the soil,” said Dr.Pratt.

Monica Grady, a planetary scientist at the Natural History Museum, London, shares this view.“We cannot risk starting a global experiment that would wipe out the precious information we are looking for,” she said. “This is just wrong.”

1. What does the underline word “programme” in paragraph 1 most probably mean?
A.progress
B.prepare
C.project
D.procedure
2. What could prove the existence of microbes living in Mars’ soil?
A.Liquid water on Mars.
B.Some creatures on Mars.
C.A lot of good soil on Mars.
D.Signs of methane in Mars’ atmosphere.
3. What can we infer from the passage?
A.Water is a key factor for life; without it, living on Mars would be impossible.
B.The project won’t affect the native life forms supposed to live on Mars.
C.The ides turning Mars into a little earth is nothing but science fiction.
D.Monica Grady is in favour of carrying out the little earth project.
4. What is the passage mainly about?
A.A plan turning Mars into a little earth.
B.The necessity of changing Mars.
C.Finding water on Mars.
D.Mars supporting life.
2023-06-17更新 | 36次组卷
阅读理解-阅读单选(约440词) | 适中 (0.65)
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【推荐3】The idea that humans might one day live on another planet has become more and more possible thanks to science, but it still seems very far away. But what British physicist Stephen Hawking said at Oxford University in the UK made that “one day” feel a lot more real and closer.

According to Hawking, we humans only have about 1,000 years left on Earth under the threats of climate change, nuclear weapons and robots. Our beat chance to survive will be to move to another planet, “so a disaster on Earth would not mean the end of the human race”, he said.

Fortunately, we have already found that planet — Mars. In fact, the National Aeronautics and Space Administration (NASA) has found strong evidence last year that liquid water flows on Mars. This made the idea of living there look even more hopeful.

In fact, the speed of Mars exploration seems to have been greeting faster every day over the past few years.

In 2013, for example,the Dutch company Mars One started the first project to put humans on Mars in the mid-2020s. They offered people one-way tickets to go and build a new home on the red planet. Even if it means they’ll never come back to Earth, over 200,000 people still applied for the project, which is now in its last stages of narrowing that number down to 24.

In September, Elon Musk, the founder of US company SpaceX, also revealed a plan to get humans to Mars in six years. To meet that goal, the company is working on building larger and stronger rockets that can carry more passengers. Musk is also planning to develop a system that can produce fuel on Mars using water and carbon dioxide so that spaceships can fly back to Earth.

But staying on Mars for a few days is one thing, and living there for the rest of your life is another.

For starters, humans cannot breathe the air on Mars, so a way to keep making oxygen is needed. Dust storms also happen often on Mars, making farming there difficult. The radiation from the sun id dangerous too, because Mars doesn’t have an atmosphere like Earth’s to give people protection.

But Hawking himself seems to be looking on the bright side. He believes that we will work things out just in time, as long as we “remember to look up at the stars and not down at our feet”, he said.

1. According to Hawking, _________.
A.Mars will be the perfect planet for the human race.
B.We should work harder to push forward space exploration
C.Mankind is pushing Earth to a quick end.
D.There is not much time left for humans to move to other planets.
2. Which of the following statements is TRUE according to the article?
A.Mars is the only planet that gas water on in in our solar system, except for Earth.
B.There is an increasing interest in Mars exploration these days.
C.The project by Mars One and SpaceX aim to take lots of people to Mars.
D.The impossibility of coming back to Earth has slowed down the speed of Mars exploration.
3. The author wrote Paragraphs 7 and 8 mainly to tell us that _________.
A.No other planets can provide a better living environment than earth.
B.Living conditions on Mars are very unpleasant for humans.
C.We still have to solve many problems before we can settle on Mars.
D.We should try to fond another planet that is more livable than Mars.
4. According to the text, what’s the future of living on Mars?
A.Uncertain.B.Optimist.C.Impractical.D.Pessimistic.
2021-07-26更新 | 49次组卷
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