Using animals to test drugs intended for humans is controversial, with critics arguing there are other ways to ensure new medicines are safe and effective. But the scientists who carry out the research say animal studies remain necessary. Statistics indicate that in the UK around three million mice are being used for research and tens of millions worldwide.

Despite the difference in appearances, the genetic similarities with humans are     1    . The mouse genome (基因组) shares over 95% of its genes with humans. The animal acts as a “model”, genetically     2     to develop a human disease. But the use of mice, like any animal, in research is criticized by some.

Animal Defenders International (ADI) is one of the groups that campaigns for an end to the use of animals in research. “We would argue that it is extremely outdated, and not very good science for humans,” says Fleur Dawes of ADI. Ms. Dawes believes the suffering that the animals go through does not legalize their     3     to science and medicine for humans.” There is a big problem with that because there are huge differences between the species. And even though there are similarities with humans and mice, they react very differently to each other when experimented on. So what works in one animal is not an indication that that is how things work in other animals.”

However, Dr. Wells from Mary Lyon Centre (MLC) says they are constantly trying to     4     the process to reduce the suffering of mice.” If it’s a procedure where you can anaesthetize (麻醉) the mice, then you do it to reduce their stress. And if there is a (n)     5     method that doesn’t involve mice, you are not legally and normally allowed to do the procedure.”

If we     6     animal research, are there alternatives? Dr. Wells says, “There is a massive field     7     on alternatives, and we are very supportive of that field and we always keep track of what is going on in that field, because maybe we can replace one of our models. “Those alternatives include chips on human organs to study their function, micro-dosing treatments in humans and     8     models.” Lots of people say that there is a computer now to model what is going to happen in diseases,” Dr. Wells adds, “But we still don’t know enough to program those computers with     9     knowledge to be able to model what’s happening in every disease.”

Fleur Dawes agrees one alternative is not enough. But she says, “By combining the different alternatives, you can actually get a much better picture that is of much better     10     to humans.”

3 . Directions: Fill in each blank with a proper word chosen from the box. Each word can be used only once. Note that there is one word more than you need.

One of the British royal traditions is that the king or queen can     1     ownership of any unmarked mute swan in open water in Britain. For many years, this tradition was     2     with Queen Elizabeth II. Every summer, the swans on the River Thames would be counted for Her Majesty. Now, with Britain having King Charles III on the throne, this centuries-old tradition known as the Swan Upping will continue to be     3     over five days during the third week of every July.

Several years ago, when I was living in London, I went along to     4     the tradition for myself. It was a completely enjoyable experience. School kids and elderly watchers gathered ahead of the day’s launch in Marlow (马洛，一个英国城镇) to meet the Royal Swan Marker — Queen Elizabeth II’s     5     in her absence — David Barber, and other Swan Uppers, or catchers.

The Uppers themselves are a mix of old boys and younger men-all dressed in uniforms. They paddle their way upriver in a fleet of wooden boats, shiny with gold detailing. Flags flutter behind them in the     6    .

The small fleet is     7     by an armada (舰队) of watchers. A boatload of journalists is there for the     8    . Hug e passenger boats cruise alongside, trying to get a view of each catch.

Not long after, the traditional call goes out: “All up!” it’s the first catch of the day. The Uppers carefully     9     their boats around the birds, moving closer, before catching and tying them. The young swans are taken ashore and     10    , measured and recorded with rings attached to their legs. And the adult swans are checked against the records. Then the young birds are released with their family, unharmed.

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.”

Fifteen wild Asian elephants that left their     1     in Xishuangbanna National Nature Reserve(保护区)in Yunnan province have so far not caused any trouble in the provincial capital(省会), Kunming, thanks to local authorities’ effective measures. By Thursday afternoon, the herd(兽群)had moved to Shuanghe county, Jinning district in Kunming’s outskirts, according to the Yunnan Forestry and Grassland Administration, which has     2     a special work team under the guidance of the provincial government.

Provincial forestry police have followed the elephants’ movements round the clock, using drones(无人机)and cameras. Experts from both the national and provincial forestry departments are advising on     3     to control the elephants. Police and firefighters in Kunming are working to prevent the elephants from coming into     4     with residents. Trucks(卡车)and digging equipment have been put in place at the     5     of villages to try to stop the pachyderms’(厚皮动物)entry.

A woman from Ganhe village, where the elephants     6     around for several hours on Thursday, told local media that they had received     7     from the village committee. “All my family members moved to the second floor of our house on Wednesday. We were very nervous last night, but     8     no one was hurt,” she said.

Although it’s not known when the elephants left the Xishuangbanna reserve, experts believe they may have started roaming(徜徉)last year and are now about 500 kilometers away from the reserve.

The Asian elephants, which are listed as endangered(濒危的)on the International Union for Conservation of Nature Red List of Threatened Species,     9     Class-A protection status in China, the same level afforded(给予)the giant panda. Yunnan is the only home to wild Asian elephants in China and has 300 of the animals. However, more than two-thirds of the population live outside nature reserves, said Chen Mingyong, a life sciences professor at Yunnan University who has been     10     wild elephants for decades.

Cats are     1     for their indifference to humans: Almost any owner will testify to how     2     these animals ignore us when we call them. But according to a study published Thursday in Scientific Reports, domestic cats do recognize their own names - even if they walk away when they hear them.

Atsuko Saito, a behavioral scientist at the University of Tokyo, previously showed that cats can recognize their owners’ voices. In her latest study she     3     this down, investigating whether they respond to hearing their names. The study included 78 cats from Japanese     4     and a ”cat cafe.“ (Such cafes, where patrons can interact with felines, are popular in Tokyo and have started to catch on in London and New York.)

During their experiments Saito and her colleagues used what behavioral psychologists call the habituation-dishabituation method. This involves repeatedly exposing a subject to a stimulus (in this case a spoken word) until the subject no longer     5     any reaction. Then the subject is presented with a test stimulus ( in this case, its name), and researchers observe whether it reacts. This step helps rule out responses to random stimuli.

For the new study, the scientists first had cat owners repeatedly say four words that were similar to their cats’ names, until the cats habituated to those words. Next the owners said the actual names, and the researchers looked at whether individual cats (when living among other cats) appeared able to distinguish their monikers. The cats had more pronounced responses to their own names - moving their ears, heads or tails, or meowing - than to similar words or other cats’ names.

Then the researchers had people unfamiliar to the cats speak the names, to test whether the cats still recognized them. Although their responses were less     6     than when their owners called them, they still appeared to recognize their names after being habituated to other words.

”This new study clearly shows that many cats react to their own names when spoken by their owners,“ says biologist John Bradshaw, who studies human-animal interactions at the University of Bristol’s Anthrozoology Institute and was not involved in the new study. But Bradshaw says he is less     7     cats can recognize their names when spoken by someone unfamiliar. ” I think that it’s entirely possible that some cats are able to     8     between one human voice and another, but I’d like to see more trials before I’d say that the evidence is compelling,“ he says.

Saito says she thinks feline pets learn to recognize their names because of what is in it for them. ”I think cats associated their names with some rewards or punishments,“ she says - adding that she thinks it is unlikely the cats understand their names are     9     to them. ”There is no evidence that cats have the ability to recognize themselves, like us,“ she explains. ”So, the recognition about their name is different from ours.“ Still, she says, it may be possible to teach cats to recognize other words. Whether that could allow humans to train cats to respond to commands - as dogs readily do -- is another matter.

”Cats are just as good as dogs at learning,“ Bradshaw says. ”They’re just not as keen to show their owners what they’ve learned.“ Most cat owners would     10     agree.

White tigers are so rare in the wild that they have been seen only a few times in recorded history. Their rarity could be because of the rare gene or because they lack adequate camouflage (保护色),     1     their ability to catch prey or avoid other predators.

But they are not     2     n captivity. Because they are so rare, exhibitors and collectors seek to     3     white tiger populations for the sake of generating profit. To continue producing white tigers,     4     tigers with this rare gene are intensively inbred over multiple generations. In other words, parents are bred with their offspring and siblings are bred with one another.

Some places breed and abuse white tigers under the guise (以……为幌子) of conservation (保护). Captive-bred white tigers     5     absolutely no conservation or educational purpose. Due to their lack of genetic diversity, high degree of inbreeding and resultant diseases, these animals have no place in any conservation program, so no legal conservation organization today supports the breeding of white tigers.

The only reason white tigers are bred today is because they are     6     profitable for breeders and exhibitors who charge visitors at entertainment venues to play with cubs (幼狮), using them as photo props (摄影道具). Once cubs age out of this vicious pay-for-play system, they may be sold to the general public as “pets,” intensively bred to create the next generation of money- making white tiger cubs or otherwise     7     to cruel treatment. When the     8     public buys into an exhibitor’s false conservation claims and pays to see or handle a white tiger, they are unknowingly allowing irresponsible inbreeding, poor population management and exploitative practices to continue.

Pop culture has     9     the keeping and breeding of tigers and other big cats in a terribly harmful way. Now that our collective eyes are open to what we need to do to protect these magnificent animals, we must reduce their greatest     10    : us.