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.”

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.

Deadly virus approaches tigers

India’s most important tiger conservation body is to investigate growing concern that Asia’s wild tigers are     1     to a deadly new disease.

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     2    for a number of years.

There have been     3    of CDV in wild tigers in other areas. According to Dr Dale Miquelle of the Wildlife Conservation Society, quite a few tigers were either killed or seriously affected by a disease that was probably CDV in 2010. And the Sikhote-Alin Biosphere Reserve has also reported a(n)     4     decline in tiger numbers.

CDV may also exist in the tiger population in Sumatra, where animals have been reported to be behaving     5    and losing their fear of humans.

Dr John Lewis of the British charity Wildlife Vets International is helping the Sumatran    6    to fight the risk by training local vets in what he calls “the world’s first tiger- disease monitoring program”.

Lewis also believes that the way CDV changes tigers’ behavior could be a factor where tiger- human     7    are an issue. This could be true of the Sundarbans, a large area shared by India and Bangladesh where man-eating is spreading.

Perhaps we should not be surprised that tigers are     8    with CDV. In 2004, it killed 1,000 lions in the Serengeti in Tanzania, and as wildlife reserves are    9    surrounded by people with dogs, the problem is only likely to get worse.

But as Miquelle told BBC Wildlife, “Very few people were aware of the potential threat, let alone looking for it, even if it is     10    in the system. But at least now they are.”

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     1     (call) ‘Summly’. It was an app     2     summarized stories in the news, and it was downloaded by nearly a million people. Last month, an Internet giant     3     (buy) his app for $30 million.

“The moment when I’m proudest for     4     has been seeing these tweets coming through from teenagers, saying ‘You’ve inspired me.’ I’m so excited about that,” says Nick. His mother says she was never worried about the amount of time he was spending on the computer, “because he would always show us what he was doing. I remember him     5     (create) 3D models on his computer as a 10-year-old.”

Nick isn’t a stereotypical computer nerd.     6     is he arrogant or self-centred, which you might expect of a boy who     7     (describe) as a ‘genius’ since 12 years old. He is polite, likeable, enthusiastic and self-aware. He enjoys the humanities, cricket and rugby. He doesn’t want to work in computer programming. He’s more interested in product design.

What is he going to do with the money from his app? One thing he’d like to do is     8     (invest ) in small companies. “That’s what is exciting, and if you are lucky to have a bit of money, you can take those risks. That’s what I would do if I was going to spend it.”

When asked     9     Summly can do, he says that, “It helps publishers reach out to a younger audience.” He feels that young people are interested in the news, but they don’t want to spend time reading long stories if they’re not relevant to their lives.     10     Summly, one can quickly find out whether a story might be interesting.

9 . Google is my doctor

When illustrator Scott Adams lost his voice, his doctors were confused.     1     It turned out that Scott was suffering from spasmodic dysphonia-a neurological disorder affecting the muscles to voice. With the help of Google Alerts and advice from his doctors, Scott got in touch with an expert in the US and had special surgery on his throat to cure his problem. He is now a firm believer of using the Internet for self-diagnosis.

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.     2     But the Internet can provide a vast number of specialized experts, and Googling can help you tap in to that.

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.     3     Doctors also take into account your medical history, state of mind, etc. So no computerized symptoms checklist can equal a complete professional assessment.

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.     4    .

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 _________ for it are obvious: we encourage our youth to be successful and success, as everyone knows, is partly down to having the right _________. But when nine-year-olds hi re image consultants, you have to wonder: could things have gone too far?

Some of those caring most about image are _________. They know that everything — clothes, posture, voice—influences what people think of you and _________ , has to be carefully managed. In the 1960 US presidential debate, those listening on the radio believed that Nixon won, while those watching on TV believed Kennedy was the _________. The difference was that Kennedy was wearing make-up but Nixon wasn’t, and the viewers were _________ by his appearance.

Celebrities seek help from wardrobe, hair stylists, make-up artists and more just to manage their profile, and these professionals don’t come _________. Mari a Moriati, stylist to some of Hollywood’s A-listers, is said to be paid $10,000-20,000 a time to choose the clothes for a celebrity on a press tour. She will pack each outfit including detailed _________(‘roll up the sleeves twice and undo the top button of the shirt’).

It’s not just them that need an image boost. The cities, too, try to give themselves the marketing _________ of a style makeover. They know that most of the tourists don’t have the time to think in detail about where they want to go on holiday and instead __________ a few simple preconceptions of what a place is like. Those preconceptions are easy to __________ on people with an advertising campaign or a catchy slogan.

So, perhaps we should step back from our __________ in image and focus on what is important. Ignore the gossip and the websites telling us to manage our online profile and instead depend on __________ rather than image to reach decisions. All these suggestions sound sensible, but are they __________? How much research will we really do before deciding which celebrity we like or where to go on our next holiday?

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) __________ place and image is important. Lucy is just taking control of hers.’