Scientists have long assumed that most of the ice that melte

共用题干
Europa's Watery Underworld

Europa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be
deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where
scientists find liquid water,they hope to find life as well.
Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's
surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns
on Europa and concluded that the formations mark the top of an underground pool that holds as much water
as the U.S.Great Lakes.
Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash
of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For
more than 10 years,scientists have wondered what causes the formations.The new study suggests that they
arise from the mixing of vast underground stores of liquid water with icy material near the surface.
For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about
the new lake is exciting.
"It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked on
the study,told Science News."But even if they didn't,they say that Europa is doing something interesting
and active right now."
Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos
terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma-
tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland.
Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something
similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the
surface fractures.This would explain the jumbled ice sculptures.
"Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on
Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains
to form quickly on Europa.
The new study suggests that on this moon,elements such as oxygen from the surface blend with the
deep bodies of water. That mixture may create an environment that supports life.

Schmidt and her colleagues are the first group of scientists reaching Europa.
A:Right
B:Wrong
C:Not mentioned

共用题干
U. S. Scientists Confirm Water on Mars
NASA scientists said that Mars was covered once by vast lakes,flowing rivers and a Va-riety of other wet environments that had the potential to support life.
Laboratory tests aboard NASA's Phoenix Mars Lander have identified water in a soil sample;the lander's robotic arm delivered the sample Wednesday to an instrument that iden-tifies vapors produced by the heating of samples.
“We have water,”said William Boynton of the University of Arizona,lead scientist for ,the Thermal and Evolved-Gas Analyzer,or TEGA.“This is the first time Martian water has been touched and tasted.”
The robotic arm is a critical part of the Phoenix Mars mission. It is needed to trench into the icy layers of northern polar Mars and deliver samples to instruments that will analyze what Mars is made of,what its water is like,and whether it is or has ever been a possible habitat for life.
The soil sample came from a trench approximately 2 inches deep.When the robotic arm first reached that depth,it hit a hard layer of frozen soil.Two attempts to deliver samples of icy soil on days when fresh material was exposed were foiled when the samples became stuck inside the scoop.Most of the material in Wednesday's sample had been exposed to the air for two days,letting some of the water in the sample vaporize away and making the soil easier to handle.
“Mars is giving us some surprises,”said Phoenix principal investigator Peter Smith of the University of Arizona.“We're excited because surprises are where discoveries come from. One surprise is how the soil is behaving. The ice-rich layers stick to the scoop when poised in the sun above the deck,different from what we expected,from all the Mars simulation tes-ting we've done so far.”
Since landing on May 25,Phoenix has been studying soil with a chemistry lab,TEGA, a microscope,a conductivity probe and cameras.The science team is trying to determine whether the water ice ever thaws enough to be available for biology and if carbon-containing chemicals and other raw materials for life are present.
The mission is examining the sky as well as the ground. A Canadian instrument is using a laser beam to study dust and clouds overhead.
“It's a 30-watt light bulb giving us a laser show on Mars,”said Victoria Hipkin of the Canadian Space Agency.
A full-circle,color panorama of Phoenix's surroundings also has been completed by the spacecraft.
“The details and patterns we see in the ground show an ice-dominated terrain as far as the eye can see,”said Mark Lemmon of Texas A & M University,lead scientist for
Phoenix's Surface Stereo Imager camera.“They help us plan measurements we're making within reach of the robotic arm and interpret those measurements on a wider scale.”

Which one of the following statements is NOT meant by the writer?
A: Scientists have been trying to break the ice-rich layers of soil on Mars.
B: Scientists have been surprised by how the soil on Mars behaves.
C: Scientists have been trying to find out if there is life supporting material on Mars.
D: Scientists have been trying to know if water ice will melt.

共用题干
1. Icebergs are among nature's most spectacular（壮观的）creations , and yet most people have never seen one.A vague air of mystery envelops them.They come into being somewhere in faraway, frigid waters,amid thunderous noise and splashing turbulence,which in most case no one hears or sees. They exist only a short time and then slowly waste away（消融）just as unnoticed.
2. Objects of sheerest（最纯粹的）beauty they have been called. Appearing in an endless vaniety of shapes,they may be dazzlingly white,or they may be glassy blue,green or purple,tinted faintly on in darker hues.They are graceful, stately,inspiring in calm,sunlight seas.
3.But they are also called frightening and dangerous,and that they are一in the night,in the fog,and in storms.Even in clear weather one is wise to stay a safe distance away from them.Most of their bulk is hidden below the water,so their underwater parts may extend out far beyond the visible top.Also,they may roll over unexpectedly,churning the waters around them.
4.Icebergs are parts of glaciers that break off,drift into the water,float about awhile,and finally melt.Icebergs afloat today are made of snowflakes that have fallen over long ages of time.They embody snows that drifted down hundreds,or many thousands,or in some cases maybe a million years ago.The snows fell in polar region and on cold mountains,where they melted only a little or not at all,and so collected to great depths over the years and centuries.As each year's snow accumulation lay on the surface,evaporation and melting caused the snowflakes slowly to lose their feathery points and become tiny grains of ice.When new snow fell on top of the old,it too turned to icy grains.So blankets of snow and ice grains mounted layer upon layer and were of such great thickness that the weight of the upper layers compressed the lower ones.With time and pressure from above, the many small ice grains joined and changed to larger crystals,and eventually the deeper crystals merged into a solid mass of ice.

With time and pressure from above,the many small ice grains joined and changed to__________, and eventually the deeper crystals merged into a solid mass of ice.
A:larger than the part above the water
B:stay near the iceberg
C:melt away just as unnoticed
D:larger crystals
E:stay away from iceberg
F:above the water

Friends might not be always trust-worthy, but dogs are; they have long been regarded as the most( )company of human beings.

A.reliable
B.regular
C.reluctant
D.religious

共用题干
Europa's Watery Underworld

Europa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be
deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where
scientists find liquid water,they hope to find life as well.
Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's
surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns
on Europa and concluded that the formations mark the top of an underground pool that holds as much water
as the U.S.Great Lakes.
Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash
of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For
more than 10 years,scientists have wondered what causes the formations.The new study suggests that they
arise from the mixing of vast underground stores of liquid water with icy material near the surface.
For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about
the new lake is exciting.
"It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked on
the study,told Science News."But even if they didn't,they say that Europa is doing something interesting
and active right now."
Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos
terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma-
tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland.
Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something
similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the
surface fractures.This would explain the jumbled ice sculptures.
"Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on
Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains
to form quickly on Europa.
The new study suggests that on this moon,elements such as oxygen from the surface blend with the
deep bodies of water. That mixture may create an environment that supports life.

The liquid water of an underground pool of Europa is estimated as much as the volume of the U.S.Great Lakes.
A:Right
B:Wrong
C:Not mentioned