3 . Scientists have not found any signs of life on Mars yet,but they say a robotic vehicle called “Curiosity” is helping them learn a lot about the planet’s history and climate.

Curiosity landed on Mars in August 2012 after travelling through space for more than eight months.It was sent to Mars by scientists from NASA in the United States.

Curiosity is about the size of a car and has six wheels.It also has a robotic arm,cameras,and instruments that allow it to examine things it finds on the surface.Then it sends the information back to the earth.

Curiosity’s main task is to find out if anything could live on Mars,either now or in the past.On Nov.2,NASA scientists held a press conference (新闻发布会) to discuss what Curiosity had found in its first two months on Mars.

Curiosity has found soil that is similar to the sand formed by volcanoes (火山) on the earth.Scientists say that studying the minerals in Martian soil will help them understand what conditions were like on the planet in the past.Curiosity also found smooth stones like the ones found on river beds and seashores on the earth,where their rough edges have been worn down by water.Mars is very cold and dry now,but scientists say the smooth stones tell them that a river used to run through the place where they were found.

Curiosity has been testing the atmosphere around Mars for a type of gas called methane (甲烷),but so far it has not found any.On the earth,most methane is produced by plants or animals.Methane on Mars might indicate that some type of tiny plants or animals lived there.

Curiosity is the fourth robotic vehicle to be sent to Mars.It will continue to explore the planet for about two years.

1. Which of the following descriptions about Curiosity is TRUE?

A．It landed on Mars in January 2012.

B．It is small in size and has four arms.

C．It took over eight months to arrive in Mars.

D．It was sent to Mars by scientists from Russia.

2. According to the information sent back by Curiosity,scientists believe that 　　　.

A．there’s no air on Mars	B．Mars is warm and wet now
C．the soil on Mars is rich	D．there used to be water on Mars

3. The underlined word “they” in Paragraph 5 refers to “　　　”.

A．smooth stones	B．rivers
C．robotic vehicles	D．volcanoes

4. We know from the sixth paragraph that 　　　.

A．some tiny animals once lived on Mars

B．there are no plants or animals on Mars now

C．the atmosphere around Mars is full of methane

D．Curiosity is designed to test the atmosphere around the earth

5. What is the main idea of the passage?

A．Humans benefit a lot by going to Mars.

B．Scientists will stop the research on Mars soon.

C．It is possible to build an earth-like environment on Mars.

D．A robotic vehicle helps scientists get useful information from Mars.

4 . The Milky Way is full of habitable (宜居) places, with roughly half of all sunlike stars hosting Earth-size worlds that could be friendly to life.

Here’s a good sign for alien hunters: More than 300 million worlds with similar   conditions to Earth are spread throughout the Milky Way galaxy. A new analysis concludes that roughly half of the galaxy’s sunlike stars host rocky worlds in habitable zones where liquid water could pool or flow over the planets’ surfaces.

Astronomers estimated the number of these planets using data from NASA’s planet-hunting Kepler spacecraft. For nine years, Kepler stared at the stars and watched for the brief twinkles produced when orbiting planets block a portion of their star’s light. By the end of its mission in 2018, Kepler had spotted some 2,800 exoplanets (外星行星) — many of them nothing like the worlds orbiting our sun.

But Kepler’s primary goal was always to determine how common planets like Earth are. The calculation required help from the European Space Agency’s Gaia spacecraft, which monitors stars across the galaxy. With Gaia’s observations in hand, scientists were finally able to determine that the Milky Way is populated by hundreds of millions of Earth-size planets orbiting sunlike stars — and that the nearest one is probably within 20 light-years of the solar system.

It took more than half a century for scientists to start pinning down how many planets could possibly host life. In 1961, astronomers knew of no worlds orbiting stars other than the sun — and although planetary formation theories suggested exoplanets should be common, we had no observational evidence that they existed. But over the past decade, it’s become clear that planets are extremely common, outnumbering stars in the Milky Way. On average, nearly every star is home to at least one orbiting world.

Early estimates suggested that perhaps 20 percent of sunlike stars hosted a world that   met those criteria. We now know that the number is closer to 50 percent, if not more.

Of course, many factors determine whether a world in the habitable zone is truly friendly for life. Planetary characteristics such as magnetic fields, atmospheres, and plate tectonics all play a role, and those are difficult to observe on small, faraway worlds.

1. When the author says, “Here’s a good sign for alien hunters”, he probably means____.

A．that’s good news for hunters

B．we will find aliens soon

C．there is a clear signal from alien

D．many sunlike stars have been found that may be habitable

2. How did Kepler work to find exoplanets?

A．By observing the brief flicker that occurs when orbiting planets block some of the star’s light.

B．By using the data from the European Space Agency’s Gaia spacecraft.

C．By calculating the stars in the galaxy.

D．Through its own calculation.

3. What can we infer from paragraph 4?

A．Kepler’s primary goal was to make sure that the Earth is a common planet.

B．Kepler helped Gaia to calculate the planets.

C．Gaia is only 20 light-years away from the solar system.

D．Kepler monitors stars across the Milky Way.

4. What does paragraph 5 mainly talk about?

A．The importance of planetary formation theories.

B．Exoplanets are common.

C．Scientists spent more than half a century to find out how many planets host life.

D．Astronomers have known of no worlds orbiting stars other than the sun since 1961.

5. Many factors determine whether a world in the habitable zone is truly friendly for life EXCEPT____.

A．oxygen

B．atmospheres

C．magnetic fields

D．plate tectonics

5 . It seems that we are one step closer to finding alien life and maybe a future home for humanity. Scientists from NASA have found a new solar system filled with planets that look like the Earth and could even support life.

The group of seven planets, which orbits a star called Trappist-1, is 39 light years away from the Earth in the constellation of Aquarius(水瓶座). And three of them are in the “habitable zone” - the area around a star where water is most likely to be found. This is important because water is necessary for life.

“This is an amazing planetary(行星的) system - not only because we have found so many planets, but because they are all surprisingly similar in size to the Earth”, astronomer Michael Gillon from the University of Liege in Belgium told The Independent.

Trappist-1 is a “dwarf star(矮星)” which is colder and shines dimmer than our sun. If a person were on one of the seven planets, everything would look a lot darker than usual. The amount of light heading toward our eyes would be about 200 times less than we get from the sun, according to The Independent.

Because of that, Trappist-1, together with many other dwarf stars, was never on the list of places where scientists looked for alien life. But Michael Gillon, lead researcher behind the discovery, decided to give dwarf stars a chance. He built a telescope in Chile to observe 60 of the closest dwarf stars, and it turned out that Trappist-1 was worthy of the effort.

The researchers hope that they can spend more time watching the newly found planets to learn more about them. Even though more research is needed before determining whether these planets could really support life, the discovery is still encouraging. It shows just how many Earth-size planets could be out there.

“[The discovery] gives us a hint that finding a second Earth is not just a matter of if, but when,” NASA scientist Thomas Zurbuchen told The Telegraph.

1. What can be learned about the new solar system from the text?

A．It contains a sun and planets like the Earth.

B．Seven planets move around Trappist-1.

C．Water can be found on all of the planets.

D．There are aliens on the planets.

2. Why is this new planetary system amazing?

A．The size of the planets is similar to that of the Earth.

B．It has the same number of planets as our solar system.

C．Scientists have found alien life in the new solar system.

D．The planets are more suitable for humans to live than the Earth.

3. Why didn't other scientists observe dwarf stars?

A．It is impossible to find alien life on the planets of Trappist-1 and other dwarf stars.

B．Scientists did not find a good place to observe dwarf stars according to the passage.

C．Trappist-1 and other dwarf stars don't provide as much heat and light as our sun can.

D．Scientists have observed dwarf stars, but they failed to find the possibility of survival.

4. What does the underlined word “dimmer” mean?

A．Stronger

B．More powerful

C．Less bright

D．Less beautiful.

5. What is the main idea of this text?

A．Scientists have found a second Earth.

B．People will move to another Earth soon.

C．Scientists are planning to explore another planet.

D．A new solar system may become home for humans.

6 . In the long discussion of water on the Moon, a new study contradicts (与……相矛盾) some recent reports that say the Moon had water at the time of its formation. A group of researchers report in the journal Science that when the Moon was created, some 4. 5 billion years ago, there was not much hydrogen (氢气) on it, and therefore no water.

The researchers surveyed and evaluated this by analyzing chlorine (氯) isotopes found in lunar rock samples from Apollo missions. The range of chlorine isotopes in lunar samples was 25 times that found in samples from Earth.

“If the Moon had significant levels of hydrogen, as Earth did, this range would have been far less,” said Zachary D. Sharp, a scientist in the Department of Earth and Planetary Sciences and the study’s lead author.

“The chlorine would have stuck together with hydrogen, forming compounds like hydrogen chloride, and escaped from the Moon’s surface,” he said. The abundance of chlorine indicates a lack of hydrogen and water.

“The amount of water on the Moon was too low for life to possibly have existed there,” he said.

Most scientists believe the Moon was formed when a large object struck Earth, breaking off a chunk (a vast piece) that has since orbited Earth.

On Earth, goes one theory, water was released as steam from molten basalts (玄武岩) over time, eventually forming bodies of water.

“An understanding of whether the Moon was dry or wet will help us understand how water appeared on Earth,” Dr. Sharp said.

1. A new study indicates that ______ on the moon.

A．there is plenty of water	B．water is unlikely to exist
C．water existed in the past	D．there is a little water now

2. The author would like to tell us ______ through the sixth paragraph.

A．why there is no water on the Moon	B．how the Moon was formed
C．when the Earth struck the Moon	D．where the Moon orbited

3. What does the underlined word “this” stand for in the second paragraph?

A．Neither hydrogen nor water on the Moon.

B．Too much chlorine isotopes on the Moon.

C．Not being much hydrogen, no water on the Moon.

D．More chlorine exists on the Moon than Earth.

4. Which of the following is NOT TRUE according to the passage?

A．Zachary D. Sharp, a scientist in the Department of Earth and Planetary Sciences was in charge of the new study.

B．Chlorine isotopes are 25 times on the Moon larger than on Earth.

C．The more abundant chloride, the shorter hydrogen and water.

D．The new study is beneficial to understand how water appeared on Earth.

5. What can we learn from the passage?

A．There is enough water and hydrogen on the Moon.

B．Hydrogen chloride easily escaped from the Moon’s surface.

C．The Earth had significant levels of hydrogen.

D．Water on Earth is directly from molten basalts.

7 . Round and Round They Go

Space is becoming more crowded. On December 3, a Falcon 9 rocket made by SpaceX thundered into the sky. On board were 64 small satellites, more than any American company had launched before in one go.They have a variety of uses, from space-based radar to the monitoring of radio-frequency emissions.

These objects are part of the latest breed of low-Earth-orbit (LEO) satellites. This launch is just a taste of what is planned. SpaceX and OneWeb, a communications firm, plan to launch satellites in their thousands, not hundreds. The pair are set to double the total number of satellites in orbit by2027.

For that to happen,however,three worries must be overcome. Debris (碎片) is the most familiar concern.As long ago as 1978, Donald Kessler,a scientist at NASA, proposed a situation in which, when enough satellites were packed into low-Earth orbits, any collision could cause a chain reaction which would eventually destroy all space craft in its orbital plane (平面).The syndrome which bears Mr. Kessler's name weighs heavily on the minds of executives at the new satellite firms.Debris could cause entire tracts (广阔的一片) of space to be unusable for decades.

Solutions exist. One is to grab malfunctioning satellites and pull them down into-Earth's atmosphere.Another is to monitor space more intensively for debris; a US Air Force programme called Space Fence is due to start in 2019. But technology is only part of the answer. Rules are needed to govern the safe disposal (清除) of old satellites from low-Earth orbit. The United States' Federal Communications Commission is revising its regulations with this in mind. Other countries should follow suit.

Cyber-security is a second, long-standing worry. Hackers could take control of a satellite and seal intellectual property, redirect data flows or cause a collision. The satellite industry has been slow to respond to such concerns. But as more of the world's population comes to rely on the infrastructure of space for access to the internet, the need for action intensifies.

The third issue follows from the first two. If a simple mistake or a cyber-attack can cause a chain reaction which wipes out hundreds of billions of dollars of investment, who is liable?Underwriters (保险商) are studying the plans of firms that wish to operate large numbers of satellites.But there is a long way to go before the risks are well understood,let alone priced.

As space becomes more commercialized, mind-bending prospects open up: packages moved across the planet in minutes by rocket rather than by plane, equipment sent to other small planets, passengers launched into orbit and beyond. All that and more may come,one day. But such activities would raise the same questions as LEO satellites do. They must be answered before the space economy can truly develop.

1. What can we learn about LEO satellites from the passage?

A．They are supposed to limit the space economy.

B．They are expected to increase in large numbers.

C．They are designed to move beyond the Earth as far as possible.

D．They are mainly intended to bring internet connectivity to remote areas.

2. To deal with debris in space,the author suggests________.

A．depending entirely on the modern technology

B．monitoring the movement of spaceships carefully

C．strengthening rules to remove old satellites safely

D．destroying all the satellites with problems instantly

3. What does the underlined word "intensify"in Paragraph 4 probably mean?

A．Measure.

B．Increase.

C．Spread.

D．Repeat.

4. Which of the following can be classified as the third worry?

A．Lack of satellite regulations.

B．Loss of intellectual property.

C．Crisis of confidence in the field.

D．Slow response of satellite industry.

5. What is the author’s attitude toward the launch of LEO satellites?

A．It should be further confirmed for it ownership.

B．It should be continued because of its advantages.

C．It should be done carefully to avoid potential risks.

D．It should be stopped in face of the space economy.

8 . The ringed planet Saturn has 53 known moons. And another one may be on the way. NASA’s Cassini-Huyens space probe has spotted（发现）a small shape in Saturn’s outermost ring. It suggests the existence of a new moon. The moon has not been directly spotted yet, but scientists have already given it a nickname---Peggy.

The probe’s findings were published in the journal Icarus. Casssini has been observing the ringed planet and its surroundings since 2004. Saturn is a big and powerful world. With a diameter of 74, 732 miles, it is 9½ times the size of Earth. It spins very quickly, and take only 11 hours to spin fully on its axis(轴). The planet is located about 885.9 million miles from the sun and has an average temperature of -285 degrees Fahrenheit.

Peggy will be joining a large community. Saturn has thousands of rings. The outermost ring, called the A Ring, is the largest and brightest. It measures 750 miles long and 6 miles wide. Saturn’s rings are made up of rock, dust and ice, and are constantly gathering space matter. As this material gathers and clumps together, moons are born.

If Peggy is a new moon, it is also a tiny one, measuring only 0.5 miles in diameter. But there is no telling how big this baby will grow over time. “We’ve never seen anything like this before,” said astronomer Carl Murray in a statement . He is the lead author of the Icarus report. “We may be looking at an act of birth, where this object is leaving the rings and heading off to be a moon in its own right.” Once that happens, it will be given a formal name.

However, this mini moon may be one of Saturn’s last. The formation of all its moons, new and old, big and small, has used up much of the rings’ raw material. After 4.5 billion years, Saturn may have finally revealed all its babies.

1. Which of the following is TRUE about Saturn?

A．It has hundreds of rings.	B．It is much bigger than Earth.
C．It moves as quickly as Earth.	D．Its 53rd known moon is called Peggy.

2. What does the underlined word“It”in Paragraph3 refer to?

A．Saturn’s biggest moon.	B．Saturn’s innermost ring.
C．Saturn’s outermost ring.	D．Saturn’s new moon Peggy.

3. We can infer from Paragraph 4 that .

A．Peggy may disappear soon

B．Peggy may grow bigger and bigger

C．Peggy will have its own moon soon

D．Peggy is the new moon’s formal name

4. According to the last paragraph,     .

A．Saturn will have more and more moons

B．Saturn’s rings will have more and more material

C．Saturn’s rings may disappear in 4.5 billion years

D．Saturn won’t have too many moons younger than Peggy

5. Which can be the best title for the text?

A．Saturn’s baby moon	B．The future of Saturn
C．Saturn’s beautiful rings	D．Interesting facts about Saturn

9 . Are we alone in the universe? A team of scientists announced on January 6, 2015 that they had identified eight planets beyond our solar system, three or four of which orbit in their stars’ “Goldilocks Zone” — the region where temperatures are not too hot or too cold for water, which is a necessary ingredient for life as we know it, to exist liquid form. This may be good news for people hoping that Earth is not the only inhabited world in the universe.

The scientists, led by Dr. Guilermo Torres of the Harvard-Smithsonian Center for Astrophysics, made the discoveries using data collected by the planet-seeking Kepler telescope.

NASA launched Kepler in 2009. Since then, the telescope has identified more than 1,000 planets outside of our solar system. Torres and his team analyzed the data about the eight newly discovered world to determine which ones are most likely to be similar to our Earth.

Among the new discoveries, the scientists say the planets called Kepler438b and 442b are the closest to Earth. Kepler 438b is just about 10% larger than our planet, and gets 40% more of its energy from its star than Earth receives from the Sun. Temperatures there would be about 140 degrees. Kepler 442b is about 33% larger than Earth, but receives 30% less energy from its star. That would make it a potentially chillier world than our own. Torres says it is possible for life to exist and survive in either of those temperatures, but for that to happen, these planets would need to have another key ingredient for life: a heat-trapping atmosphere like Earth’s.

While these findings add to the possibility that life exists beyond Earth, Torres cautions against drawing conclusions, “We are not claiming they are inhabited,” he says. In fact, these planets are so far away that the scientists cannot observe them directly, which can be explanation for why for now it remains unknown whether these planets contain life. But the discovery of planets in their stars’ habitable zones suggests that somewhere out there, some form of alien life may have taken hold.

1. The scientists have identified eight planets, ________.

A．which are suitable for humans to live on

B．some of which are possible for life to exist on

C．some of which have the same situations as Earth

D．which are not too hot or too cold for water to exist on

2. Which statement about the discovery of Torres and his team is TRUE?

A．Kepler 438b is too hot for any life to exist on.

B．Kepler 438b and 442b are the farthest to Earth.

C．They have made the discoveries through Kepler.

D．They have discovered over 1000 planets in 7 years.

3. What is the possible thing that Kepler 442b lacks for life to exist on?

A．The water	B．The sunlight
C．The soil	D．The atmosphere

4. About their exploration, Torres wants to indicate that ________.

A．there is a lot left to learn

B．they have had decisive gains

C．it is the first in human history

D．it is certain for life on the planets

5. Which can be the best title for this passage?

A．Are We Alone?

B．Eye on the Stars

C．Discover Another Earth

D．Discovery of New Stars to Live on