A massive fire tore through the main market in the city of Hargeisa in northern Somalia overnight, injuring about two dozen people and     1    (destroy) hundreds of businesses, officials have said.

Images     2    (post) on social media showed flames and huge clouds of smoke in the night sky over the city, the capital of the breakaway region of Somaliland. The cause of the blaze     3     devastated the sprawling Waheen market, the lifeblood of the city and home     4     an estimated 2,000 shops and stalls, is not yet known.

Officials said it started on Friday evening but was largely brought under control by dawn on Saturday, although some small areas were still burning.

“The town has never witnessed such a massive calamity,” Hargeisa’s mayor, Abdikarim Ahmed Mooge, told reporters at the scene. “This place was the economic centre of Hargeisa and     5     the firefighters’ best efforts made to contain the fire, the market is destroyed.” He said the blaze could have been brought under control before causing such extensive damage but that the firefighters’ attempt     6    (deny) due to access problems. The vast market is a crowded warren of shops and makeshift stalls, with no proper streets, only narrow pathways.

The Somaliland president, Muse Bihi Abdi, said during a visit to Waheen     7    about 28 people, nine of them women, were injured, but that so far no loss of life     8    (report). He said the government would be releasing one million dollars to help with the emergency response to the disaster.

Hargeisa chamber of commerce chairman Jamal Aideed said the loss of the market was immense     9     it accounted for 40% to 50% of the city’s economy.

“I have lost everything tonight, this fire was the biggest I have ever seen in my life,” said market trader Bashi Ali. “I had several businesses in the market and all of them burned to ashes.     10    we can learn from this disaster is to plan the market well,” he added.

Norway is Teaching Travelers to Travel

After 15 people died during Easter in 1967, the Norwegian Trekking Association and the Red Cross announced their campaign ‘Welcome to the mountains, but be responsible’. Fjellvettreglene, the ‘mountain code’     1     encourages people to have a healthy and respectful relationship with nature, has since become a crucial part of Norwegian culture. It includes points such as bringing necessary equipment   to assist yourself and others,     2    (seek)shelter if necessary and feeling no shame in turning around.

Nationally, Norway     3     (experience) an 11% increase in tourism in the past decade. Trolltunga, a piece of rock,     4     (see) 1,800 visitors in one 2017 day alone. Why? Because people want the same picture they see on Instagram and Facebook. A lot don’t care     5     the experience of the hike. They just want proof that they did it.     6     this tourism boom is good for the economy, it has become a threat to   Norway’s natural environment.

    7    (use) toilet paper, abandoned bottles and plastic bags can be found littered all around Trolltunga. And with the high amount of people who come unprepared for such an active hike, Norway’s leading hiking group, Friluftsliv, also has called for regulations on the number of tourists hiking to Trolltunga. Lasse Heimdal, leader of the outdoor organization said, “On a busy day, you may have to wait in line for an hour and a half just     8    (get) a picture. To control this, we’d like to regulate     9     people can hike in a day. Starting hike times should also have regulations so people don’t start too late and find     10     trapped here.”

Wolves have a certain undeserved reputation: fierce, dangerous, good for hunting down deer and farmers’ livestock. However, wolves have a softer, more social side, one that has been embraced by a heart-warming new initiative.

In a bid to save some of Europe’s last wolves, scientists have explored the willingness of these supposedly fierce creatures to help others of their kind. Female wolves, the scientists have discovered, make excellent foster parents to wolf cubs that are not their own. The study, published in Zoo Biology, suggests that captive-bred wolf cubs(幼兽) could be placed with wild wolf families, boosting the wild population.

The gray wolf was once the world’s most widely distributed mammal, but it became extinct as a result of widespread habitat destruction and the deliberate killing of wolves suspected of preying on livestock. Fear and hatred of the wolf have since become culturally rooted, fuelled by myths, fables and stories.

       In Scandinavia, the gray wolf is endangered, the remaining population found by just five animals. As a result, European wolves are severely inbred and have little genetic variability（变异性）, making them vulnerable to threats, such as outbreaks of disease that they can’t adapt to quickly. So Inger Scharis and Mats Amundin of Linkoping University, in Sweden, started Europe’s first gray wolf-fostering program. They worked with wolves kept at seven zoos across Scandinavia. Eight wolf cubs between four and six days old were removed from their natural parents and placed with other wolf packs in other zoos. The foster mothers accepted the new cubs placed in their midst.

The welfare of the foster cubs and the wolves’ natural behavior were monitored using a system of surveillance cameras. The foster cubs had a similar growth rate as their step siblings in the recipient litter, as well as their biological siblings in the source litter. The foster cubs had a better overall survival rate, with 73% surviving until 33 weeks, than their biological siblings left behind, of which 63% survived. That rate of survival is similar to that seen in wild wolf cubs. Scientists believe that wolves can recognize their young, but this study suggests they can only do so once cubs are somewhere between three to seven weeks of age.

If captive-bred cubs can be placed with wild-living families, which already have cubs of a similar age, not only will they have a good chance of survival, but they could help dramatically increase the diversity of the wild population, say the researchers. Just like the wild wolves they would join, these foster cubs would need protection from hunting. Their arrival could help preserve the future of one of nature’s most iconic and polarizing animals.

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7 . For millions of years, Arctic sea ice has expanded and shrunk in a rhythmic dance with the summer sun. Humans evolved in this icy world, and civilization relied on it for climatic, ecological and political stability. But now the world comes ever closer to a future without ice. The National Snow and Ice Data Center reported that 2019’s minimum arctic sea ice extent was the second lowest on record. Arctic summers could become mostly ice-free in 30 years, and possibly sooner if current trends continue. As the northern sea ice declines, the world must unite to preserve what remains of the Arctic.

Although most people have never seen the sea ice, its effects are never far away. By reflecting sunlight, Arctic ice acts as Earth’s air conditioner. Once dark water replaces brilliant ice, Earth could warm substantially, equivalent to the warming caused by the additional release of a trillion tons of carbon dioxide (CO₂) into the atmosphere and declining sea ice threatens wildlife, from the polar bear to algae that grow beneath the sea ice, supporting the large amount of marine life.

To avoid the consequences the scientific community should advocate not just for lowering greenhouse gas emissions, but also for protecting the Arctic from exploitation. The Antarctic shows the way. In the 1950s, countries raced to claim the Antarctic continent for resources and military installations. Enter the scientists. The 1957-1958 International Geophysical Year brought together scientists from competing countries to study Antarctica, and countries temporarily suspended their territorial disputes (争议). In 1959, 12 countries signed the Antarctic Treaty to preserve the continent for peaceful scientific discovery rather than territorial and military gain.

Sixty years later, we must now save the Arctic. A new Marine Arctic Peace Sanctuary (MAPS) Treaty would protect the Arctic Ocean as a scientific preserve for peaceful purposes only. Similar to Antarctica, MAPS would prohibit resource exploitation, commercial fishing and shipping, and military exercises. So far, only 2 non-Arctic countries have signed MAPS; 97 more need to sign on to enact it into law. Scientists can help—just as they did for the Antarctic—by giving statements of support, asking scientific organizations to endorse (支持) the treaty, communicating the importance of protecting the arctic to the public and policy-makers, and above all, by convincing national leaders to sign the treaty. In particular, Arctic nations must agree that recognizing the arctic as an international preserve is better than fighting over it. In 2018, these countries successfully negotiated a 16-year moratorium on commercial fishing in the Arctic high seas, demonstrating that such agreements are possible.

Humans have only ever lived in a world topped by ice. Can we now work together to protect Arctic ecosystems, keep the northern peace, and allow the sea ice to return?

8 . In the 1966 science-fiction movie One Million Years B. C., the movie characters had a time travel and arrived in an ancient landscape inhabited by dinosaurs and early humans. The movie was low on science and high on fiction: by then dinosaurs were long dead and modern humans were millions of years away.

A more accurate picture of Earth’s inhabitants at the time is now being revealed. In research published in Nature, a team of scientists led by Anders Gotherstrom at the University of Stockholm, and Love Dalen at the Centre for Palaeogenetics (古遗传学), also in Sweden, describe sequencing (测序) DNA samples from mammoths (猛犸象) that lived and died in north-eastern Siberia around a million years ago.

The team’s work represents a new record, for their mammoth DNA is, by some half a million years, the oldest ever successfully reconstructed. Extracted (提取) from horses, bears and even Neanderthals and Denisovans, two close cousins of modern humans, such ancient DNA has proved an invaluable tool for investigating the past. Although fossils preserve the basic physical features of extinct animals, they are silent about many crucial details that even an incomplete genome (基因组) can help to fill in.

The trouble with DNA is that it breaks down after death. The more broken down it is, the harder it is to sequence. Scientists think that, after about 6m years, all that would be left would be individual base pairs (碱基对), the equivalent of trying to reconstruct a book from several letters. Under the right conditions, however, such as the extreme cold of Arctic permafrost (冻土层) this decay can be slowed.

Dr. Dalen and his colleagues were interested in three mammoth molars (臼齿) extracted in the 1970s from Siberian geological layers that suggested great age. Samples from each were sent to Dr. Dalen’s laboratory in 2017. Having checked they had not been contaminated by bacteria or the shaking hands of Paleontologists, the DNA were extracted, sequenced, and dated. Whereas DNA samples from a living animal can run to several hundreds of thousands of letters, the ancient mammoth samples yielded merely dozens of letter long. This is close to the limit of what is scientifically usable, says a biologist named Ludovic Orlando.