3 . Edmund Halley was an English scientist who lived over 200 years ago. He studied the observations of comets which other scientists had made. The orbit of one particular comet was a very difficult mathematical problem. He could not figure it out. Neither could other scientists who dealt with such problems.

However, Halley had a friend named Newton, who was a brilliant mathematician. Newton thought he had already worked out that problem, but he could not find the papers on which he had done it. He told Halley that the orbit of a comet had the shape of an ellipse.

Now Halley set to work. He figured out the orbits of some of the comets that had been observed by scientists. He made a surprising discovery. The comets that had appeared in the years 1531, 1607, and 1682 all had the same orbit. Yet their appearances had been 75 to 76 years apart.

This seemed very strange to Halley. The different comets followed the same orbit. The more Halley thought about it, the more he thought that there had not been three different comets, as people thought. He decided that they had simply seen the same comet three times. The comet had gone away and had come back again.

It was an astonishing idea! Halley felt certain enough to make a prediction of what comet would happen in the future. He decided that this comet would appear in the year 1758. There were 53 years to go before Halley’s prediction could be tested. In 1758 the comet appeared in the sky. Halley did not see it, for he had died some years before. Ever since then that comet has been called Halley’s comet, in his honor.

4 . Step into Moving to Mars, an exhibition of Mars mission and colony design at London's Design Museum, and immediately you have good reasons not to move there.

Frightening texts on the walls announce that Mars wasn't made for you; that there is no life and precious little water; that, dressed in a spacesuit, you will never touch, taste or smell the planet you now call “home”. As Lisa Grossman wrote for New Scientist a couple of years ago, “What's different about Mars is that there is nothing to do there except try not to die.”

It is an odd beginning for such a celebratory exhibition, but it provides a valuable, dark background against which the rest of the show can sparkle (闪耀)—a show that is, as its chief manager Justin McGuirk remarks, “not about Mars; this is an exhibition about people”.

Moving along, there is a quick yet clear flash through what the science fiction writer Kim Stanley Robinson calls “the history of Mars in the human mind”. A Babylonian clay tablet and a Greek vase speak of early ideas about the planet. A poster for the original Total Recall film reminds us of Mars's psychological threat.

The main part of the show is our current plans for the Red Planet. There are real spacesuits and models of 3D­printed Martian settlements and suitable clothing and furniture. Mission architecture and engineering sketches line the walls. Real hammers meant for the International Space Station are wall­mounted (固定在墙上的) beside a low­gravity table that has yet to leave and may indeed never leave Earth.

This, of course, is the great strength of approaching science through design: reality and assumptions can be given equal visual weight, drawing us into an informed conversation about what it is that we actually want from a future on Mars.

5 . It is in human nature to explore new things. To that end, many countries have been exploring space for many decades, particularly the US, Russia, and countries in Europe.

President Xi Jinping praised the success of the Chang’e 5 mission (使命) in bringing back the country’s first samples (样本) collected from the moon. The whole country is proud of this breakthrough. The Chang’e 5 mission has achieved many significant breakthroughs, including China’s first lunar (月球的) surface sampling, first liftoff from the moon and the first spacecraft with the ability to gather and meet in lunar orbit with samples to re-enter the Earth s atmosphere.

The success of the Chang’e 5 mission marks a conclusion of China’s current lunar exploration project. The successful re-entry and landing of the Chang’e 5 capsule (太空舱) have enabled China to obtain its first lunar samples, marking a new start for lunar and planetary research. With this achievement, China sets a new milestone in space exploration.

No matter how far China goes into space, it always stays true to its original mission-uncovering the secrets of the universe and contributing to human’s peaceful use of space. China is a peace-loving country and will use its achievements for promoting peace around the globe.

China views these efforts as part of the world’s lunar exploration. It chose a different landing site and is promising to share its samples to enrich the planet’s knowledge. Some foreign scientists have shown particular interest. The exploration is not for commercial purposes, but international scientific research. Human beings shall explore the moon together, as it will finally need large projects requiring international cooperation. China will play a leadership role in the international scientific community.

6 . The year is 2094.It has been announced that a comet (彗星) is heading towards the earth.Most of it will miss our planet,but two pieces will probably _______ the southern half of the earth.

On 17 July,a piece four kilometers wide enters the earth’s _______ with a massive explosion.About half of the piece is destroyed,but the _______ part hits the South Atlantic at 200 times the speed of _______.The sea _______ and a huge hole is made in the sea bed.Huge waves are created and spread out from the hole.The wall of water,a kilometer high,rushes towards southern Africa at 800 kilometers an hour.Cities on the African coast are totally destroyed and millions of people are killed.

Before the waves reach South America, the second piece of the comet_______ in Argentina.Earthquakes and volcanoes are _______ off in the Andes Mountains.The shock _______ move north into California and all around the Pacific Ocean.The cities of Los Angeles,San Francisco and Tokyo are completely _______ by earthquakes.Millions of people in the southern half of the earth are already dead,and the north won’t be safe for long.Because of the explosions,the sun is ________ by clouds of dust,temperature around the world falls to almost zero.Crops are ruined.The sun won’t be seen again for many years.Wars ________ as countries fight for ________.A year later,no more than 10 million people remain on the earth.

Could it really________?In fact, it has already happened more than once in the history of the earth.Science shows that the dinosaurs (恐龙) ________ on the earth for over 160 million years.Then 65 million years ago they suddenly disappeared.Many scientists believe that the earth was hit by a piece of heavenly object.The dinosaurs couldn’t live ________ the cold climate that followed and they died out.Will we meet the same end?

7 . Why should mankind explore space? Why should money, time and effort be spent exploring and researching something with so few apparent benefits? Why should resources be spent on space rather than on conditions and people on Earth? These are questions that, understandably, are very often asked.

Perhaps the best answer lies in our genetic makeup as human beings. What drove our ancestors to move from the trees into the plains, and on into all possible areas and environments? The wider the spread of a species, the better its chance of survival. Perhaps the best reason for exploring space is this genetic tendency to expand wherever possible.

Nearly every successful civilization has explored, because by doing so, any dangers in surrounding areas can be identified and prepared for. Without knowledge, we may be completely destroyed by the danger. With knowledge, we can lessen its effects.

Exploration also allows minerals and other potential resources to be found. Even if we have no immediate need of them, they will perhaps be useful later. Resources may be more than physical possessions. Knowledge or techniques have been acquired through exploration. The techniques may have medical applications which can improve the length or quality of our lives. We have already benefited from other spin-offs including improvements in earthquake prediction, in satellites for weather forecasting and in communications systems. Even non-stick pans and mirrored sunglasses are by-products (副产品) of technological developments in the space industry.

While many resources are spent on what seems a small return, the exploration of space allows creative, brave and intelligent members of our species to focus on what may serve to save us. While space may hold many wonders and explanations of how the universe was formed or how it works, it also holds dangers. The danger exists, but knowledge can help human being to survive. Without the ability to reach out across space, the chance to save ourselves might not exist.

While Earth is the only planet known to support life, surely the adaptive ability of humans would allow us to live on other planets. It is true that the lifestyle would be different, but human life and cultures have adapted in the past and surely could in the future.

What will it be like to live on the moon?Volunteers    1    (live)in Yuegong­1,a closed lab    2    imitates a moon­like environment at Beihang University in Beijing,might be able to answer this question.

In January,four volunteers finished spending 200 days in the lab.Never    3    any person stayed in a closed lab for such a long period of time before the volunteers had their try.It was tough for the volunteers to have both body and mind    4    (adjust)to the environment in the closed lab.    5    their credits,the volunteers set a world record for the    6    (long)stay in a closed lab.

Life in Yuegong­1 is busy.Volunteers get up at 8：30 am and go to bed at 11 pm.Growing food    7    (be)their daily routine.There are more than 30 kinds of vegetables and fruit for them to grow and eat.Volunteers need to record their body temperature,blood    8    (press)and mental state every day.Scientists outside the lab use these data    9    (monitor)their health.

The experiment will give scientists information that can be used to create better living areas for    10    (astronaut)in space,the Xinhua News Agency reported.

9 . Do you think alien beings exist somewhere in the universe? It seems like Mars, our closest neighbor, has inspired the most science fiction as the place where aliens are most likely to come from. Recent Mars probes (探测) have shown us that there is no life on that planet—at least not now. But that does not mean that life does not exist elsewhere—after all, the universe is really big. A lot of scientific research is going on in the search for “extraterrestrial life”.

Think about it—why should the seven billion people on this little planet be the only living beings in the universe? It would, in fact, seem logical that this is not the case. So scientific research in this matter is based around the idea of finding other planets that have environments that can support life —environments similar to the Earth. The search is on for the evidence of the existence, or earlier existence of life: from very wise beings to simple organisms (有机物).

So far, there have been a number of theories as to which planetary bodies may have an atmosphere that can support such life and therefore deserve closer attention. As for places within our own Milky Way Galaxy, it has been assumed over the decades that Mars and Venus, as well as some of the moons of Jupiter and Saturn, may have been hosts for life. Now, as technologies have improved and we can obtain measurements of the composition of the atmosphere on extra-solar planets, the chances of finding “alien” life forms are increasing.

There has been a theory that some of the planets in the habitable zone of the red dwarf star Gliese 581 may be able to support life. In 2007, scientists discovered exoplanet Gliese 581c—and felt that its atmosphere was most suitable for supporting life. But further research revealed that it would not. Now, attention has been turned to Gliese 581d, at the outer edge of the star’s habitable zone. The main standards for deciding whether a planetary body can be life-supporting are atmospheric conditions which allow the existence of water. Gliese 581 is about 20. 4 light years away from the Earth, so even if life does exist there, the distance would mean that communication would be unlikely.

Having said this—who says alien life forms (if they exist) need water?

10 . How big is space? That is a question man has been asking since the beginning of time. When your grandparents were in school, it was ________that the universe was very________perhaps only 5, 000 light years________. 500 years ago people considered that the universe was only a little bit________than the earth. In modern times with the________of technology we are finally starting to________the immense（无边的）size of the universe, and it is much bigger than anyone________have ever imagined.

Scientists cannot stretch（伸展）a measuring tape from the earth to a nearby star, so________do they know how far away they are? Scientists use something________parallax（视差）. Parallax means________that they look at how much the stars move in the sky________throughout the year as the earth circles the sun. This is not something________to you. In fact if you stretch out your hand in front of you and________your thumb, while________one eye, and then the other, your thumb will________to move back and forth. Stars do the________thing, but our eyes are too close to see the________. However, if we take a picture while on one side of the earth's orbit, and then take another when we get to the________side of the orbit, then we have a large enough________that we can see the stars' parallax, and________how far away they really are.