With full preparation from both China and the US, the giant panda family Mei Xiang, Tian Tian, and their 3-year-old son Xiao Qiji arrived safely in China on Thursday due to the ending of the agreement between the two     1     (country). After returning, they     2     (transport) to the Wolong National Nature Reserve, according to China Daily. The news immediately became     3     hot topic on China’s social media platform, with nearly 43 million netizens     4     (express) their joy and excitement.

    5     (prepare) for their returning, China selected senior workers to travel to the US     6     advance to take part in the panda’s feeding and help US experts in conducting behavior training and daily check-ups. What’s more, indoor animal houses, feed processing rooms and outdoor exercise areas were set up in the reserve for their isolation (隔离).

Giant pandas are rare and endangered wild animals,     7     are beloved by people around the world, and they also serve as ambassadors for     8     (culture) exchange between China and other nations. In the future, China     9     (continue) to strengthen cooperation with others, to     10     (active) contribute to the protection of endangered species such as giant pandas and the promotion of friendship between Chinese and the rest of the world.

5 . With their beautiful feathers, roosters might be forgiven for secretly taking quick looks in the mirror—especially as research now suggests the birds may be able to recognise themselves.

The ability to recognise oneself in the mirror has so far been found in a handful of animals, including elephants, dolphins, and certain fish and birds. Sonja Hillemacher, one of the authors of the study at the University of Bonn, said animals that can recognise themselves in a mirror often seemed to have more advanced cognitive abilities, and that there was a link to social and emotional wisdom, as well as self-awareness. “This ability is a basic aspect of cognition. It is also important for us,” she said.

Writing in the journal Plos One, Hillemacher and her colleagues note that roosters tend to call out to their fellow chickens if they see a threat. If a rooster is alone, however, it does not usually raise the alarm as it could draw the enemy’s attention.

In the experiment, the team placed a rooster in an indoor space and then placed a mirror, or another rooster, or nothing. The team then showed the image of a flying hawk (鹰) onto the ceiling in the space.

The results from 58 roosters found that the birds made far more alarm calls when they could see another rooster nearby, with 1.33 alarm calls per bird on average over three tests, than when alone (0.29 calls on average) or faced with the mirror (0.43 calls on average). In the follow-up experiment, the team found a similar reduction in calls when they placed a second rooster out of sight behind the mirror. The team said the findings suggest the birds did not regard their reflection as another rooster, even when there was also the presence of smell and sound of a second bird, which proves that roosters may recognise themselves in a mirror.

6 . Each year, the discovery of new shark species underlines how little we know about ocean biodiversity. In a recent report conducted by Sibert and Rubin, they reported an unexpected finding: a large-scale extinction of sharks in the pelagic ocean, the largest ecosystem on Earth, about 19 million years ago. Their discovery suggests that some extinctions in the open sea of the past may have been mysterious.

The study of Sibert and Rubin takes advantage of a system by using tiny, hard bits of shark skin and bony fish teeth that naturally fall from their bodies to the seafloor. These extremely small fossils provide a rich record of ancient oceanic sharks and their abundance for thousands of years. By studying fossils from many regions, the diversity patterns can give major insights into evolution (进化) of the open sea that would be otherwise unknown.

Sibert and Rubin quantified(量化)a past extinction of sharks, reporting a 90% decline in number and >70% drop in diversity. They found that nearer-shore sharks appear to survive, but migratory ones go extinct. The finding of this study is that sharks had undergone a widespread extinction that reorganized their communities from 16 million to 20 million years ago.

Sibert and Rubin narrowed the disappearance of sharks to a window of time under 100,000 years around 19 million years ago, but the causes of this event remain unclear. Because this time period does not stand out as a period of major climatic change, the authors do not attribute(归因于) environmental factors as an extinction driver. As for other causes, the loss of shark diversity is directly linked to overfishing.

The loss of sharks from the oceans has profound, complex, and unavoidable ecological consequences because their presence reflects the stability of marine ecosystems. Yet, one-quarter of the global diversity of sharks is currently threatened with extinction. Despite recent improvements in conservation actions, shark communities never recovered from a mysterious extinction event 19 million years ago; the ecological fate of what remains is now in our hands.

7 . The most powerful hurricane in the year was crashing into coastlines in Virginia. Lucky Dog Animal Rescue planned to take the 21 dogs, affected by the disaster, to a ________ in South Carolina, which became crowded as people near the coast were evacuating.

Mirah Horowitz is the head of Lucky Dog in Arlington, Virginia. “It’s a double ________,” she said. Her group found it hard to help the dogs as well as drive them from Virginia to South Carolina ________ a seven-hour trip. Then they have to put dogs in wooden boxes and bring them to the Washington, D.C., area. Finally, they had to make sure there were enough families to ________ the dogs.

The group tried to ________ more dogs from South Carolina over the weekend. They were going to hold an adoption (领养) event on September 8 at the shelter in the Washington, D.C., area. Horowitz and her colleagues decided to take some dogs and emailed ________ that night looking for families to adopt the dogs. “We had to find people to take those animals between 10 p.m. and 6 a.m.” Horowitz said. ________, they were getting many replies until 2 a.m. from people who were willing to help, after hours of ________ waiting.

Lucky Dog was also talking to an animal shelter on the island of Grand Bahama in the Bahamas. That was where the hurricane had caused the most ________ so far. The workers there did not know the dogs’ situations. ________, they heard reports of heavy flooding that had ________ the shelter. Horowitz’s group also has a helicopter which is ready to offer flights to ________ some emergency supplies.

Horowitz said, “I really ________ the help from those families. It feels nice to save animals from areas ________ by severe weather and it is ________ to make all the efforts.”

8 . Sleep is so important that it has long interested scientists. Scientists have studied everything from mice to fruit flies in the lab to get a better understanding of what happens when animals sleep and why they do it. However, gathering data (数据) on how animals sleep in their natural habitat has always been hard to do.

But scientists did just that with wild chinstrap penguins in Antarctica. In doing so, researchers found the birds took over ten thousand microsleeps throughout the day — adding up to a 11-hour-long sleep.

To study the penguins, scientists put devices (设备) into a small group of penguins’ brain and neck muscles, which provided the brain wave and location data. The devices had never been used before, so this data collection was only supposed to be a test. However, the process went so well and the data was published in this study.

Researchers found that the microsleeps last only seconds. Researchers think that being able to sleep for such a short time might help the animals avoid predators (捕食者) that might more likely attack if the penguins were asleep for longer — especially when one parent goes out feeding in the ocean for days, leaving the other parent to protect the eggs from predatory birds.

The study is an early insight into a relatively large missing scientific knowledge about sleep.

“Almost every study on sleeping birds discovers something new, something we didn’t know about before,” says study co-author Paul-Antoine Libourel.

Vladyslav Vyazovskiy, a sleep neuroscientist at the University of Oxford who didn’t join in the study, is excited about this new data because “most of what we know about the animal sleep was gained in laboratory conditions, which are totally different from conditions where sleep developed”.

9 . If there was to be a praise to the frog, it would have to contain one new piece of information: its ability to predict earthquakes. A scientific study has suggested that they escape an area just before such disaster strikes.

The evidence, published yesterday in the Journal of Zoology, centers on a population of breeding (繁殖) frogs in Italy. It seems that, a few years ago, these creatures had suddenly escaped from their home five days before an earthquake struck their breeding ground.

The frogs’ ability to sense the earthquake is not fully understood, but 96 percent of male frogs escaped and returned a day after the danger had passed. This discovery baffled Dr. Rachel Grant, who hadn’t set out to learn about frogs’ reactions to earthquakes, but to study the effect of the lunar cycle on them. She now believes that frogs may be able to sense some signs and use them as an early-warning system for earthquakes.

Frogs are not the only creatures born with an unusual power to predict natural disasters. In 2004, elephants in Thailand made loud noises before the tsunami hit, while bats in Sri Lanka flew around in anxiety before the disaster.

While most of these animal warnings have been ignored, there are times when they have been noticed. In 1975, scientists in Haicheng, China, noticed unusual behavior in the city’s dogs and cats. They demanded the evacuation of the city, expecting a major disaster. Their warning came five-and-a-half hours before an earthquake struck, resulting in 2,000 deaths. Without the evacuation, another 150,000 people could have been killed.

“There are things we can’t see and sounds we can’t hear. But many animals can. There is a sense called electro-perception that fish and sharks use to form a picture around them, while dolphins and bats use sonar to find their way around,” says Professor Daniel Mills, an expert in animal behavior at Lincoln University.