【推荐1】New York’s Central Park has a statue dedicated to him, and there’s even been a movie about him: a sled dog named Balto. Now he is the focus of a DNA study, 90 years after he died, to see what made the dog so famously tough (坚韧).

In 1925, this Siberian husky was part of an expedition in Alaska called the serum run, the goal of which was to bring life-saving medicine to young people that were threatened by a deadly disease in the remote town of Nome, over 600 miles away. Balto led the long-distance stretch, and wound up getting most of the honor.

After Balto’s death in 1933, his remains were preserved and put on display at the Cleveland Museum of Natural History.

“Balto’s fame and the fact that he was taxidermized gave us this cool opportunity 100 years later to see what that population of sled dogs would have looked like genetically and to compare him to modern dogs,” said Katherine Moon, a postdoctoral researcher at the University of California.

Her team took skin samples from the dog’s belly and reconstructed its genome — the complete set of genes in an organism. They compared this genetic material with that of 680 contemporary dogs from 135 breeds.

Contrary to a legend that thought that Balto was half wolf — as suggested in an animated Universal Pictures film that came out in 1995 — this analysis found no evidence he had wolf blood. It turned out Balto shared ancestors with modern day Siberian Huskies and the sled dogs of Alaska and Greenland.

Moon’s team also compared Balto’s genes with the genomes of 240 other species of mammals.

This allowed researchers to determine which DNA fragments (片段) were common across all those species and have not therefore changed over the course of millions of years of evolution. This stability suggests that these fragments of DNA are associated with important functions in the animal, and that mutations (基因突变) there could be dangerous.

The bottom line from the research was that Balto had fewer potentially dangerous mutations than modern breeds of dogs did, suggesting he was healthier.

1. Why did Moon and her team study the DNA of Balto?

A．Balto saved the lives of many people.	B．Balto achieved a long-distance transport.
C．Balto was a focus of the Central Park.	D．Balto was amazingly tougher than others.

2. What does the underlined word “stability” in Paragraph 8 probably mean?

A．Gene.

B．Evolution.

C．Toughness.

D．Changelessness.

3. What did the research into the gene of Balto suggest?

A．Balto had blood of wolves.	B．Balto had fewer harmful mutations.
C．Balto was a modern husky.	D．Balto was a special mammal species.

4. What is this passage mainly about?

A．A dog’s heroic act.	B．A great honor to a dog.
C．A DNA study of a tough dog.	D．A new research into DNA.

【推荐2】How to Keep Pets Safe in a Disaster

Families with new pets may experience a number of unfamiliar situations, but figuring out what to do when facing extreme circumstances like natural disasters can be a particular challenge.     1     . The better you can prepare, the more readily you can keep you and your pets safe. Below is some advice for keeping your pets safe in a disaster.

Create a disaster plan

Preparing before a natural disaster is key to keeping everyone in your family, including your pets, safe. Stock your home with supplies needed to shelter in place in the event of an emergency, and figure out where you’ll go if you have to escape from your home.     2    .

Microchip (植入微型芯片) your pets

Have your pets microchipped and ensure your contact information is filed correctly in case your pets get lost. Pet microchips are radio-frequency identification implants (植入物).     3     . If someone finds your pet without a collar, they can have the identification checked.

Develop crate (A -f) acceptance

    4    . You can make this experience more tolerable by investing in a quality crate and getting your animal used to it in everyday life. You can start by taking your pets on short car rides in their crates - with treats, walks in the park and favorite activities before and after the journey.

    5    

Even the disaster has ended, it’s important not to let your pets run freely. They may be frightened by the visual of the aftermath. When an all-clear signal is given, ensure your pets are tied or crated before you venture out so they don’t potentially hurt themselves or become lost.

A．Always bring pets with you.

B．Be careful after the all-clear

C．Bring pets inside at the first sign of danger

D．Remember to choose a pet-friendly destination

E．They aren’t tracking devices but contain unique ID numbers

F．Pets may become anxious while experiencing a natural disaster

G．In an emergency, your pet may need to spend a long time in a crate for safety

【推荐3】Does your dog love to bury himself under your covers to sleep? Many dogs do. It is fun to think about why they might do this seemingly very human thing.     1    

Animals depend on resources.     2     Your bed is a den (窝) to your dog. Since the bed is a place where he often goes, it is part of his life. Being there makes him feel safe and happy.

When your dog is under the sheets, he feels surrounded. Feeling firm pressure can calm down anxious dogs. Some kinds of dogs even like to dig holes to relax. The pressure of the sheets probably makes his brain produce happy chemicals that give him a sense of safety and maybe even fun.

    3     This feeling is what he likes. He knows he is safe when you are there. You are a faithful friend and family member. You have marked the area as a safe zone. You spend a lot of time there.     4     Being near you when you sleep is very natural to your dog.

Dogs know that their choice of sleeping places is of great importance.     5     And the sheets give them a sense of security. Most of all, your dogs want to be under the sheets because that is where you are and the safest place is always with your family.

A．Actually, they are not afraid of danger.

B．Resources are things like food, water, and shelter.

C．In the same way, your family love you as well.

D．Their den is one of their most valuable resources.

E．Your presence also gives your dog a feeling of support.

F．As family members, you share responsibility to protect each other.

G．If you think about the way a dog sees life, it’s easy to imagine why he does so.

【推荐1】If you have a Smart TV, you’ll often find yourself lost facing so many viewing choices available. Have you ever wondered how it is that we can stream Netflix videos to our homes, in high definition, in an instant? The secret to this technological miracle is one of the most important tricks in computing: compression — to make things smaller.

The idea is simple: the smaller a file is, the more you can fit in a computer, and the faster it can be transferred (传输) over the Internet. I just saved a photo of my cat, Hashtag, in two different formats. The uncompressed image (saved as BMP file) was 36.6 megabytes, while saved as a PNG file, the photo was compressed down to just 10.8 megabytes. That’s three times less storage space, and a three times faster download if it is posted on the Internet.

Another way to make files even smaller, known as “lossy” compression, is to throw away what we don’t really need. Take a video for example. Usually, video files are very large because they have to contain lots of information to digitally reproduce the pictures and sounds. But it’s very easy to save space by removing the unnecessary details, like all of the super-quiet parts of the soundtrack that are barely perceptible if you’re not a hi-fi enthusiast wearing some expensive headphones. JPEG photos work according to the same “lossy” principles too. My photo of Hashtag as a JPEG becomes as small as just 1.3 megabytes, but I can’t really tell any difference between it and the original image.

So, why not just compress everything down to be absolutely tiny? It isn’t always the answer. Sometimes you’ll need a more powerful computer to decompress (解压) a file, and other times you’ll want to keep the originals at their maximum possible quality, especially if they are your own personal photos and videos.

But for everything else, compression is a brilliant way to do more with less, whether you’re watching Netflix, streaming Spotify, or even sharing photos of your cat online.

1. In which format is an image transferred fastest online?

A．Netflix.

B．BMP.

C．PNG.

D．JPEG.

2. Which word best replaces the underlined word “perceptible” in paragraph 3?

A．Enjoyable.

B．Acceptable

C．Noticeable.

D．Changeable.

3. Which of the following best explains “do more with less” in the last paragraph?

A．Complete more tasks with less effort to make.

B．Be more functional with smaller files to deal with.

C．Become more powerful with less space to use.

D．Make files better in quality with fewer details to lose.

4. Why does the author write the text?

A．To raise an appeal.	B．To form an opinion.
C．To analyse a phenomenon.	D．To explain a concept.

【推荐2】

①China successfully launched Mengtian into space, getting a step closer to completing the country’s Tiangong Space Station by the end of this year.

②Mengtian is the second lab module(模块)and the last major component of the country’s space station. The first lab module is Wentian which is already docked (对接)with the Tianhe core module. The three modules will form a T-shaped complex in space.

③Mengtian weighs about 23 tons. It is 17.9 meters long and has a maximum diameter of 4.2 meters. It can be further subdivided into work, resource, payload and cargo airlock cabins.While Wentian is used for biological and space life science projects, such as observing the growth of various kinds of plants, animals and microbesin space, Mengtian will be used for in-orbit experiments dedicated to physics and material sciences and will focus on micro-gravity experiments. Mengtian will also act as a backup(备份)for the core module when it is undergoing maintenance(维修). And with Mengtian in place, the space station will be able to hold more taikonauts.

④Until now, space lectures(天宫课堂), Tiangong Class”, in China’s Tiangong space station have been broadcasting live to the world, attracting much attention in society. The public, especially the youth, are looking forward to the next space lecture. There are three taikonauts on board the space station at the moment. When Shenzhou-15 arrives with a change of crew, scheduled for early December, there will be six Chinese taikonauts living and working on the space station for a time until the return of the Shenzhou-14 mission crew members.

⑤China plans to complete the in-orbit construction of the space station by the end of this year. After that, the country’s space program will enter a new decade-long development and application stage. The original plan is to send two crewed spaceships and two cargo spaceships into space every year. Meanwhile, taikonauts will stay in orbit for extended periods to maintain the station and carry out scientific and technological experiments. And in 2023,China will also develop next-generation carrier rockets and crewed spaceships to significantly enhance(提高)its space program’s overall technological capabilities.

⑥China has expressed on many occasions that it accepts international cooperation and foreign astronauts to conduct research aboard its space station. So, let’s expect to unlock more mysteries of the universe through joint global efforts.

1. Which of the following statements is TRUE about Mengtian lab module?

A．It’s the second major component of China’s space station.

B．It plays an important role in the maintenance of the space station.

C．It’s enough huge to hold a great lot of people.

D．It’s mainly used for research biological science projects.

2. What does Paragraph 3 mainly tell us about the space station?

A．Its applications.	B．Its modules.
C．Its size and shape.	D．Its livable space.

3. What is the next step for China’s space program?

A．Sending two crewed spaceships and two cargo spaceships every year.

B．Developing next-generation carrier rockets and crewed spaceships.

C．Holding more space lectures to inspire the enthusiasm of young people.

D．Developing next-generation carrier rockets and crewed spaceships.

4. What can we know from the last paragraph?

A．China is very care about the space industry.

B．China’s space industry still has a long way to go.

C．China will make a new huge success in space industry.

D．China hopes to explore space with other countries together.

【推荐1】After being lost for three decades, this tiny deer-like species has finally been rediscovered in the forests of Vietnam. The silver-backed chevrotain — also known as the Vietnamese mouse deer — is about the size of a large rabbit. They are shy, enjoy being alone, appear to walk on the hips of their hooves (蹄) and have two sharp teeth. Chevrotains typically weigh less than 5 kilograms.

Its last recorded sighting was in 1990, when a team of Vietnamese and Russian researchers obtained a dead chevrotain from a hunter. “Then nothing. So little known about it that the species was one big question mark. For so long, it has seemingly only existed as part of our imagination,” said Vietnamese biologist Any Nguyen.

One of the biggest challenges was deciding where to start the search. After several interviews with local villagers who reported seeing a grey mouse deer, a field team set three camera traps for five months. “We had these two areas separated by quite some distance — one in the southern part of Vietnam and the other much further north,” said Andrew Tilker, Asian Species Officer at the Global Wildlife Conservation. This resulted in 275 photographs of the species. The team then set up another 29 cameras in the same area, this time recording 1,881 photographs of the animal.

Tilker also warned that just because this species was found relatively easily, it doesn’t mean it’s not under threat. “This might represent the last population or one of a handful populations, in which case we need to take action immediately to put conservation measures in place to ensure its survival.”

The team is now setting out to determine how large and stable this population of chevrotains is, assess the wider distribution of the species, and explore the threats to its survival. As part of the first-ever comprehensive survey on the species, the team began camera trap surveys in October in two additional areas. They will use all of the information that they gather to set up a project that strengthens the conservation of the species across its range.

1. What can be learned about chevrotains?

A．They usually live in small groups.

B．They are a rare rabbit-sized species.

C．They weigh as much as an adult deer.

D．They’ve lived in Vietnam for 30 years.

2. What did Any Nguyen’s words suggest?

A．Chevrotains became a mystery.

B．Chevrotains didn’t exist at all.

C．It was fun to hunt for chevrotains.

D．It was too late to protect chevrotains.

3. How did the field team conduct their research?

A．By interviewing some hunters.

B．By analyzing previous studies.

C．By taking pictures of chevrotains.

D．By employing villagers as guides.

4. What is the last paragraph mainly about?

A．The threats to chevrotains.

B．The team’s main challenges.

C．The team’s new discoveries.

D．The protection of chevrotains.