Scientists have found what look like caves on Mars(火星),and say they could be protecting life from the planet’s terrible environment.

Images of the Mars caves from Northern
Arizona University
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(红外线成像器) 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(充满辐射的),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 lava flows(管状岩浆流) spread across the planet long ago.The outside of the tubes cooled,forming solid walls,while something hotter inside allowed the remaining lava to flow out,forming caves.
【小题1】What does the passage mainly talk about?

D
We are all interested in equality, but while some people try to protect the school and examination system in the name of equality, others, still in the name of equality, want only to destroy it.
Any society which is interested in equality of opportunity and standards of achievement must regularly test its pupils. The standards may be changed—no examination is perfect—but to have no tests or examinations would mean the end of equality and of standards. There are groups of people who oppose this view and who do not believe either in examinations or in any controls in school or on teachers. This would mean that everything would depend on luck since every pupil would depend on the efficiency, the values and the purpose of each teacher.
Without examinations, employers will look for employees from the highly respected schools and from families known to them－a form of favoritism will replace equality. At the moment, the bright child from an ill－respected school can show certificates to prove he or she is suitable for a job, while the lack of certificate indicates the unsuitability of a dull child attending a well－ respected school. This defense of excellence and opportunity would disappear if examinations were taken away, and tile bright child from a poor family would be a prisoner of his or her school's reputation, unable to compete for employment with the child from the favored school.
The opponents(反对者) of the examination system suggest that examinations are an evil force because they show differences between pupils. According to these people, there must be no special, different, academic class. They have even suggested that there should be no form of difference in sport or any other area: all jobs or posts should be filled by unsystematic selection. The selection would be made by people who themselves are probably selected by some computer.
53．The underlined word "favoritism" in paragraph 3 is used to describe the phenomenon that_____.
A．bright children also need certificates to get satisfying jobs
B．children from well－respected schools tend to have good jobs
C．poor children with certificates are favored in job markets
D．children attending ordinary schools achieve great success
54．What would happen if examinations were taken away according to the author?
A．There would be more opportunities and excellence.
B．Schools for bright children would lose their reputation.
C．Children from poor families would be able to change their schools.
D．Children's job opportunity would be affected by their school reputation.
55．The opponents of the examination system will agree that ________.
A．jobs should not be assigned by systematic selection
B．computers should be selected to take over many jobs
C．special classes are necessary to keep the school standards
D．schools with academic subjects should be done away with
56．The passage mainly focuses on________.
A．schools and certificates                                B．examination and equality
C．opportunity and employment                       D．standards and reputation

One year, my school report made my parents angry. On Christmas Eve, all the presents were stolen, along with our TV. My parents told me that there were no presents because Santa was very angry with my behavior over the past year. The next year on Christmas Eve I slept downstairs with a plastic sword waiting for Santa to make sure that he didn't steal the new TV. The next morning, when I woke up, I saw Santa standing there. As soon as I saw that there were no presents, I grabbed my plastic sword and ran at him, shouting angrily: "THIEF! THIEF!"
Jack
When I was young, we always had a specific room for the Christmas tree. My mom never really liked the location, so one year she moved the tree into another room. I was convinced that Santa would not know where the tree was and would get lost in our house. I was worried that he would be mad and put me on the "bad" list and would not give me any gifts because he couldn't find the tree. I came up with the idea to make signs leading from the fireplace to the tree. They said things like: "Tree this way" or "Santa, put the gifts over here." When my big brother saw them he began to laugh his head off.
Lucy
Does everyone remember going to the mall and sitting on Santa’s lap to have his picture taken at Christmas time?
Well, I used to think that if I did that, Santa would get mad bcause he would have to go all around the world and give every kid the chance to have his picture taken with him. Of course his lap would hurt and he would be very fired. I thought he might keep a copy of the picture and that would be how he decided who would be on his naughty list.
My mom couldn't get me onto Santa's lap until she made him promise I wouldn't end up on his naughty list.
Lydia
【小题1】The real reason why Jack's TV was taken away is that ______________.

Against the supposition that forest fires in Alaska, Canada and Siberia warm the climate, scientists have discovered that cooling may occur in areas where burnt trees allow more snow to mirror more sunlight into space.
This finding suggests that taking steps to prevent northern forest fires to limit the release of greenhouse gases may warm the climate in northern regions. Usually large fires destroyed forests in these areas over the past decade. Scientists predict that with climate warming, fires may occur more frequently over the next several centuries as a result of a longer fire season. Sunlight taken in by the earth tends to cause warming, while heat mirrored back into space tends to cause cooling.
This is the first study to analyze all aspects of how northern fires influence climate. Earlier studies by other scientists have suggested that fire in northern regions speed up climate warming because greenhouse gases from burning trees and plants are released into the atmosphere and thus trap heat.
Scientists found that right after the fire, large amounts of greenhouse gases entered the atmosphere and caused warming. Ozone（臭氧） levels increased, and ash from the fire fell on far-off sea ice, darkening the surface and causing more radiation from the sun to be taken in. The following spring, however, the land within the area of the fire was brighter than before the fire, because fewer trees covered the ground. Snow on the ground mirrored more sunlight back into space, leading to cooling.
“We need to find out all possible ways to reduce the growth of greenhouse gases in the atmosphere.” Scientists tracked the change in the amount of radiation entering and leaving the climate system as a result of the fire, and found a measurement closely related to the global air temperature. Typically, fire in northern regions occurs in the same area every 80 to 150 years. Scientists, however, found that when fire occurs more frequently, more radiation is lost from the earth and cooling results. Specifically, they determined when fire returns 20 years earlier than predicted, 0.5 watts per square meter of area burned are soaked up by the earth from greenhouse gases, but 0.9 watts per square meter will be sent back into space. The net effect is cooling. Watts are used to measure the rate at which energy is gained or lost from the earth.
【小题1】According to the new findings, taking steps to prevent northern forest fires may __________.

NOT all memories are sweet. Some people spend all their lives trying to forget bad experiences. Violence and traffic accidents can leave people with terrible physical and emotional scars. Often they relive experiences in nightmares.
Now American researchers think they are close to developing a pill, which will help people forget bad memories. The pill is designed to be taken immediately after a frightening experience. They hope it might reduce, or possibly wipe out, the effect of painful memories.
In November, experts tested a drug on people in the US and France. The drug stops the body releasing chemicals that fix memories in the brain. So far the research has suggested that only the emotional effects of memories may be reduced, not that the memories are wiped out. They are not sure to what degree people's memories are affected.
The research has caused a great deal of argument. Some think it is a bad idea, while others support it.
Supporters say it could lead to pills that prevent or treat soldiers' troubling memories after war. They say that there are many people who suffer from terrible memories. “Some memories can ruin people's lives. They come back to you when you don't want to have them in a daydream or nightmare. They usually come with very painful emotions,” said Roger Pitman, a professor of psychiatry at Harvard Medical School. “This could relieve a lot of that suffering.”
But those who are against the research say that maybe the pills can change people's memories and changing memories is very dangerous because memories give us our identity. They also help us all avoid the mistakes of the past.
“All of us can think of bad events in our lives that were terrible at the time but make us who we are. I'm not sure we want to wipe those memories out,” said Rebecca Dresser, a medical ethicist.
【小题1】The passage is mainly about       .