4 . Mars is no stranger to life. Seven U. S. spacecraft have successfully landed there, and all of them took microbes to the planet’s surface(though the bugs probably did not survive for long). Yet the world’s space agencies continue to maintain strict spacecraft sterilization (消毒) procedures in the hope of minimizing the spread of Earth life beyond our planet. For decades this idea — known as planetary protection—is widespread. Now, some scientists say, these procedures are preventing the search for life beyond Earth by raising costs and preventing innovative missions-without meaningful benefits.
Of all missions to Mars to date, only the Vikings, the first trip to the Red Planet, were intended to test for life. Spacecraft that went later did not have that ability. But a future mission will, and the protectionist thinking goes, a spacecraft might not be able to distinguish between a life form native to Mars and one with origins on Earth. In July 2013 astrobiologists Dirk Schulze-Makuch and Alberto Fairen argued against this in Nature Geoscience.
“If Earth life can thrive on Mars, they almost certainly already do,” the authors write. “If they cannot, the transfer of Earth life to Mars should be of no concern, as it would simply not survive.”
With clear evidence of a water y history and some signs of water present, Mars could be where we find life in our solar system. And with the development of Curiosity’s precise landing system, we can finally reach the mysterious parts of the planet. But it’s these areas that require a craft sterilization process.
In the 1970s Vikings 1 and 2 revealed what seemed like a dead planet, so planetary-protection requirements were relaxed. Now, with more knowledge of Mars’ environment, missions set to visit areas with evidence of flowing water below the surface have to meet the strict-and more costly- Vikings standards.
Finally, there’s the philosophical problem of what responsibility, if any, we have to other planets and any life we leave there. The truth is we’re never going to be able to fully protect Mars if we intend to explore it. And spreading is simply what life does.
“If we want to survive for a long time, we have to expand beyond Earth,” Schulze-Makuch says. “There’s no other way.”
1. Strict spacecraft sterilization procedures are meant to ______.A.decrease the costs of space exploration |
B.help the search for life forms beyond Earth |
C.contribute to innovative missions in the universe |
D.prevent Earth life being transferred to other planets |
A.there was no preclse landing system |
B.Mars was considered to be a lifeless planet |
C.the mysterious parts of Mars remained unknown |
D.flowing water was found below the surface of Mars |
A.Mars is now on the edge of being destroyed |
B.human beings are too ambitious to expand beyond Earth |
C.there is no need to worry about bringing Earth life to Mars |
D.we need to be responsible for keeping Mars what it is like now |
A.optimistic | B.relaxed | C.debatable | D.negative |
5 . I was in seat 10F next to the emergency exit. A few minutes after take-off there was a loud explosion. Everybody gasped (倒抽气) and there were a few screams. Then, surprisingly, it went very quiet — everyone was assessing the situation.
It soon became obvious we weren’t going back to LaGuardia Airport and that we were heading for the water. I started thinking this was it. Then I heard the announcement, ‘This is the captain, brace for impact,’ and everything suddenly got clear. I had to stop thinking about death, and instead, about what I should do once the pilot landed in the water. ‘You sat in this seat,’ I thought, ‘you’ve got to get this door open.’
At about 300 feet (91.5 meters), I started reading the instructions. There were six steps, and I had just read them two or three times when we hit the water. It felt like the worst car crash you could imagine. Fortunately, I’d just read the instructions and managed to get the door open. The wing was sinking lower and lower. I walked out onto it and walked as far along as I could to make room for other people. It was freezing, and nobody had a jacket. Some people were underwater to their waists.
It felt like half an hour before we saw the first ferry, though it could have been only five or ten minutes. I was fourth onto the ferry, and I started helping people onto the boat. To our relief, everyone had survived the crash.
I got through the whole incident by taking it one step at a time: get the door open, throw the door out, figure out if you’re sinking. I just kept on doing that until I reached solid ground. Only then did I go into the men’s room and cry for a few minutes.
1. After hearing a loud explosion, what did passengers, including the writer, do?A.They put on life jackets as instructed. |
B.They tried to figure what had happened. |
C.They couldn’t help shouting for help on end. |
D.They asked the pilot to fly to LaGuardia Airport. |
A.He sat by the emergency exit. | B.He had an experienced neighbor. |
C.He was once taught how to open it. | D.He read and understood the instructions. |
A.Humorous. | B.Aggressive. | C.Organized. | D.Expressive. |
A.No one got killed in it. | B.It happened at the end of the trip. |
C.The pilot managed to land the plane safely. | D.A ferry came to the rescue the moment it happened. |
A. authorities B. conflicts C. increasingly D. infected E. invisibly F. oddly G. outbreaks H. present I. subjected J. suspected K. unexpected |
Deadly virus approaches tigers
India’s most important tiger conservation body is to investigate growing concern that Asia’s wild tigers are
The National Tiger Conservation Authority is to fun d a study of Canine Distemper Virus(CDV) in six of the most important areas for the species, which could confirm a problem that a few experts have
There have been
CDV may also exist in the tiger population in Sumatra, where animals have been reported to be behaving
Dr John Lewis of the British charity Wildlife Vets International is helping the Sumatran
Lewis also believes that the way CDV changes tigers’ behavior could be a factor where tiger- human
Perhaps we should not be surprised that tigers are
But as Miquelle told BBC Wildlife, “Very few people were aware of the potential threat, let alone looking for it, even if it is
App-solutely amazing!
Nick D’Aloisio got his first laptop when he was nine. He started designing apps when he was 12 and at 15, he launched an iPhone app
“The moment when I’m proudest for
Nick isn’t a stereotypical computer nerd.
What is he going to do with the money from his app? One thing he’d like to do is
When asked
焚烧化石燃料(如石油、煤炭等)产生大量二氧化碳等温室气体,这些温室气体对太阳辐射中的可见光具有高度透过性,而对来自地面的长波辐射具有高度吸收性,能大量吸收地面辐射中的红外线,导致全球变暖。写一篇演讲稿,主题是“面对全球变暖,我们能做些什么?”,向同班同学宣传。
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9 . Google is my doctor
When illustrator Scott Adams lost his voice, his doctors were confused.
Adams is one of an increasing number of people who have started using the Internet to get health advice. The advantages are numerous, starting of course with the obvious convenience of getting a diagnosis from the comfort of your own home.
Diagnosing minor medical problems from information on the Internet can also have an impact on society’s medical costs. You can compare insect bites with Internet pictures, ask what type they are and whether they are dangerous without wasting your busy doctor’s precious time.
However, it must be said that diagnosis is tricky, and comparing your rash(疹子) with an online photo may lead you down the wrong path.
In conclusion, the Internet is a good starting point in diagnosing your health problems, but you should always consult your doctor before acting on anything you find there.
A.On a professional level, there is no way one doctor car be an expert in everything. |
B.It was not until he turned to the Internet that he managed to identify his condition. |
C.This condition was the very one that made him unable to speak |
D.Appearance provides only ten percent of the information needed to make a diagnosis. |
E.Do not underestimate the value of talking to real people — doctors and telephone helplines will help you put what you read into context. |
F.To sum up, if your doctor refuses to talk to you, the Internet will give you a better solution. |
10 . Miriam Glassman, a top image consultant, is standing in front of her client, Lucy. ‘Can you give me an idea of what you are looking for?’ she asks. ‘Something cool,’ says nine-year-old Lucy. Glassman gets some jackets and marches off to the changing room with Lucy. This is a growing trend and the
Some of those caring most about image are
Celebrities seek help from wardrobe, hair stylists, make-up artists and more just to manage their profile, and these professionals don’t come
It’s not just them that need an image boost. The cities, too, try to give themselves the marketing
So, perhaps we should step back from our
And going back to our image consultant, surely Glassman must have reservations about taking on such young clients? Apparently not. ‘I get so many calls from teens,’ she says. ‘School is a(n)
A.challenges | B.results | C.advantages | D.reasons |
A.consultant | B.goal | C.attitude | D.image |
A.stars | B.politicians | C.managers | D.designers |
A.therefore | B.otherwise | C.nevertheless | D.besides |
A.guide | B.winner | C.lecturer | D.officer |
A.left over | B.looked over | C.put off | D.taken on |
A.true | B.easy | C.cheap | D.plain |
A.instructions | B.budgets | C.comparisons | D.plans |
A.business | B.strategy | C.agency | D.equivalent |
A.rely on | B.approve of | C.complain of | D.work on |
A.blame | B.impose | C.congratulate | D.feed |
A.criticism | B.belief | C.suspicion | D.desire |
A.opinions | B.facts | C.advertisements | D.policies |
A.suitable | B.popular | C.realistic | D.appealing |
A.competitive | B.peaceful | C.inspiring | D.delightful |