【推荐1】Dust on furniture may be bad news for waistlines (腰围). But it’s far too early to add dusting to a weight-loss plan. Dietary fats and other materials that make up indoor dust can send a signal to human fat cells, telling them to grow. That process, in turn, might slow the body’s rate of burning energy. Such changes could add to any weight problems a person might have.
“We don’t know what that means to long-term health and certain diseases yet,” says Heather Stapleton, one of the study’s authors. But she notes that her team’s findings also raise a question of whether pollutants in dust might play some role in the growing, global problem of obesity (肥胖).
Stapleton and her colleagues collected dust from homes and offices. Studies found that some materials in the dust could turn on a protein (蛋白质) called PPAR-gamma 1. It’s found in many human tissues. Turning this protein on can cause fat cells to grow. Researchers think this protein may be involved in obesity. But a second study now finds evidence that certain fats are mostly to blame. Cooking oils may send out some of these fats into the air, where they eventually find their way into house dust. Or, the authors say, the fats might enter house dust as part of the hair or skin cells shed (脱落) by people or pets.
“While the findings are amazing,” says Mitchell Lazar, another study author, “these findings need to be taken as very limited.” Indeed, he adds several cautions about how the findings should be understood. “For one thing, people eat these fats in foods all of the time. That is likely to be a lot more than would be consumed from indoor dust,” he said.
1. What do we know about PPAR-gamma 1? _____

A．It comes from dust.

B．It leads to weight gain.

C．It can help get rid of dust.

D．It only appears in human bodies.

2. What’s the best title for the text?   _____

A．Can house dust make us fat?

B．Why is it important to clean?

C．Anything to do to deal with dust?

D．What is the best way to lose weight?

【推荐2】From the early morning, I sit, glued to the chair in front of my computer, even for hours sometimes. But one thing I try to do every day is take a ten-minute walk around midday.

Walking at lunchtime is a smart thing to do, a new study finds. This doesn’t seem like news. After all, we’ve known forever that doing exercise is good for us. But as The New York Times points out, those fitness studies typically looked at the effects of exercise plans in the long run. This new study looks at changes that happen more quickly, from one day to the next or even from this hour to the next hour.

A group of office workers who almost sit got involved in the research, all out of shape, but otherwise emotionally and physically healthy. Researchers asked them to take 30-minute lunchtime walks, three days a week for 10 weeks. The volunteers were also asked to install apps on their phones, so that the researchers could send the volunteers questions after they walked. Then the researchers used those answers to judge how the volunteers were feeling about life and work, and to measure their feelings about everything from stress and tension to motivation.

When the researchers compared the volunteers’ answers on the afternoons when they walked to those on the afternoons they didn’t walk, there was quite a difference. On the days when they had a lunchtime walk, the volunteers said they felt less stressed, more energetic and more relaxed versus(与……相对) on the days when they didn’t walk.

Unfortunately, many of the volunteers weren’t confident that they’d continue walking after the study, mainly because they were expected to work through their lunch breaks. Understandable, sad.

1. How does the new study differ from other fitness studies?

A．It focuses on the short-term effects of walking.

B．It calls on people to have a walk after lunch.

C．It mainly pays attention to office workers.

D．It aims at studying the relationship between exercise and health.

2. Why were the volunteers required to install apps on their phones?

A．To chart their time spent online.	B．To know how long they walked.
C．To respond to the researchers’ questions.	D．To prevent them from getting lost.

3. What is the finding of the new study?

A．Office workers usually have little time to go for a walk.

B．Walking brings more advantages to people than other exercise.

C．A long-time-to-sit lifestyle is linked to an increased risk of disease.

D．Lunchtime walks contribute to quickly boosting people’s mood.

4. What can we infer about the volunteers from the passage?

A．They will spend more time walking.

B．Some of them tend to be more outgoing.

C．Most of them will perform better at work.

D．They may stop lunchtime walks due to work pressure.

【推荐3】More scientists are exploring cellular senescence(衰老)—a state in which cells(细胞)no longer divide. Senescent cells, which build up in older bodies, have a link to age-related conditions such as dementia(痴呆) disease.

Scientists are exploring drugs that treat senescent cells. But the most promising tool against the bad effects of senescent cells, experts say, is exercise.

Today, LeBrasseur, who directs a center on aging at Mayo, says exercise is “the most promising tool that we have” for good health in late life, and its power spreads to our cells. Research suggests exercise prevents the buildup of senescent cells, helping the immune(免疫的)system clear them and fight the cell damage that can affect aging.

Last year, LeBrasseur led a study that provided the first sign in humans that exercise greatly affected senescence. It cut signs in the bloodstream of the effects of senescent cells in the body.

After a 12-week exercise program, researchers found that older adults had cut signs of senescence and improved body strength, physical ability and reported health.   A recent study collects even more facts—in animals and humans—for exercise as a treatment to fight against senescence cells.

While such studies are not well-known outside scientific circles, many older adults connect exercise with youthfulness. Farmer Mike Gale, 81, put in a track and field throwing circle on his large farm in California. He and some of his friends throw the discus(铁饼) and use other exercise equipment. “I'd like to be competing in my 90s,” Gale says. “Why not?”

95-year-old Richard Soller says exercise keeps him fit enough to deal with what comes his way—including the discovery that his wife of 62 years had developed dementia. The two sometimes walk the streets of their neighborhood together, holding hands. “Do as much as you can,” he says. “That should be the goal for anyone to stay healthy.”

1. What do we know about LeBrasseur?

A．He discovered the cause of aging.	B．He developed drugs to treat aging.
C．He tested with animals and humans.	D．He firstly proved exercise stops aging.

2. How did Mike Gale feel about his physical condition?

A．Uncertain.

B．Confident.

C．Doubtful.

D．Anxious.

3. Why did the author mention the 95-year-old man?

A．To support his or her ideas.	B．To encourage people to exercise.
C．To praise him for his true love.	D．To introduce activities for the old.

4. Which is the most suitable title for the text?

A．Aging Secret Comes to Light	B．Aging Diseases Seriously Affect Health
C．Exercise Is Best Tool Against Aging	D．Elderly People Can Also Live Active Life

【推荐1】The riches of the natural world aren’t spread evenly across the globe. Places like the tropical Andes (赤道安第斯山脉) in South America are packed with unique species, no place else to be found on Earth. Previously, the main explanation for the biological riches concentrated in places like the Amazon Basin was that they were such places where new species evolved at a faster rate than other parts of the world. But now, new research on bird evolution may turn that assumption on its head. Instead, it supports the idea that areas with fewer species actually tend to produce new species faster.

The researchers say the biodiversity cold spots are generally found in harsher (更严酷的) environments featuring freezing, dry and unstable conditions. Though the researchers have found these locations with few bird species tend to produce new ones at high rates, they fail to accumulate many species because the unstable conditions frequently make the new life forms die out.

The more well-known hot spots, by contrast, have accumulated their large numbers of species by being warm, hospitable and relatively stable. Indeed, the researchers have found that the countless bird species that call the Amazon home tend to be older in evolutionary terms. That actually accounts for higher species richness there.

“Our results suggest that these hots pots for biodiversity are not hot spots for the evolution of new species,” says Elizabeth Derryberry, an evolutionary biologist at the University of Tennessee. “New species do form in places like the Amazon, just not as frequently as in more extreme environments.”

The researchers managed to collect 1,940 samples (样本) representing 1,287 of the 1,306 bird species from South America. Their analysis revealed that the best predictor of whether an area would produce new species at a high rate was how many species lived there, rather than climate or geographic features like mountains. Species rich areas tended to produce new species more slowly.

On a practical level, the study’s findings add new urgency for stopping destroying ecosystems that may look dry and bare, because they may actually be nature’s hothouses for the evolution of new species.

1. What is the previous explanation for biodiversity in the Amazon Basin?

A．Its species’ strong survival abilities.

B．The immigration of foreign species.

C．The rapid evolution of new species.

D．Its vast living space for new species.

2. Why do the bird species in the Amazon tend to be older?

A．There’s less competition and more chances.

B．It constantly attracts new species to come.

C．It had extreme environments a long time ago.

D．The environment there is stable and favorable.

3. The study’s findings suggest that we should ________.

A．protect harsh ecosystems

B．help species in hot areas live longer

C．develop species-rich environments

D．limit species in biodiversity cold spots

4. What is the main idea of the text?

A．Bird species prefer to live in harsher ecosystems.

B．Species poor areas may produce new species faster.

C．Tropical areas are home to large numbers of species.

D．Hot areas are more attractive to species than cold areas.

【推荐3】Once considered an optional lifestyle choice, recycling has become a commonplace activity in most areas. One type of recycling, called downcycling, involves re-purposing a material into a new product of lesser quality.     1    

Downcycling is also known as downstream recycling. It is most common in terms of industrial materials. These products lose their value as they are recycled, which limits their capacity for new use.     2     White writing paper, for example, is often downcycled into cardboard; once downcycled to this new form, it can no longer be used as white paper again. Another example of downcycling includes the use of plastic components.

Giving products a new life is considered a good way to reuse materials and avoid waste. Once downcycled to their full capacity, however, these materials are eventually so degraded that they cannot be reused further. Since downcycled products are considered of lower quality than their original form, they cannot be used in remaking their original product.

    3     Plastic, glass, and aluminium products coded with the number one may be remade into something of equal or greater value. This type of recycling is known as upcycling, and represents the forward compatibility of recycled components. Materials available for downcycling, such as water, juice, and milk bottles, are coded with the number two.     4    

Items available for downcycling often require additional chemicals, energy, and other treatments in order to transform them into something usable. Durable plastic products in particular require much additional treatment. Trash bins, tables, and chairs are also considered materials with a high energy cost to recycle.

When a product reaches a code seven, it is considered no longer recyclable.     5     Since these products can no longer be made into new ones, they will either have to be reused or discarded, typically in a landfill.

A．These recycled materials may often be put into new use.

B．It can include varying grades of plastic, paper products, and other materials.

C．Their recycled form is typically both weaker and cheaper than their original one.

D．They may not be used to contain food-grade items again upon being downcycled.

E．Products are provided with codes to determine their grades and whether or not they may be recycled.

F．A code will determine the type of the recycled materials and give an idea of how many times they can be recycled.

G．This usually occurs when a substance is blended with other substances, such as different types of plastic with various recycling codes.

【推荐2】Awe is generally defined as the sense that you are in the presence of something larger and more consequential than yourself. According to a study called “awe walks”, people who took a fresh look at the world around them during brief, weekly walks felt more upbeat and hopeful in general than walkers who did not. Feeling a sense of awe also seems to up our overall feelings of gladness and improve health.

Previous studies have linked increased physical activity to greater happiness and reduced risks for anxiety, depression and other mental illnesses. But no studies had looked into whether mixing awe and activity might increase the benefits of each — or, on the other hand, reduce them. So, for the new study, scientists concentrated on people in their 60s, 70s and 80s, ages when some people can face risks for declining mental health.

The scientists asked 52 study volunteers to add a weekly 15-minute walk to their normal schedules. All of them were physically healthy and psychologically well-adjusted, with little disquietude or depression. Then they were randomly divided into two groups. One, as a control group, was asked to start walking, preferably outside, but given few other requirements. The members of the other group were not only asked to walk once a week, but also were instructed in how to cultivate awe as they walked. “Basically, we told them to try to go and walk somewhere new, since novelty helps to cultivate awe,” says Virginia Sturm, an associate professor who led the new study.

Both groups were asked to take a few selfies (自拍) during their walks and upload them to a lab website and also complete a daily online assessment of their current mood. After eight weeks, the scientists compared the groups’ responses and photos. Not surprisingly, the awe walkers felt happier, less upset and more socially connected than the control group members.

The findings are subjective, though, since awe, like other emotions, is difficult to quantify, but Dr. Sturm thinks awe walks could be a simple thing for small wonders without any downside.

1. What makes the new study different from the previous ones?

A．It concentrated on older people.

B．It found the solution to mental health.

C．It associated physical exercise with happiness.

D．It took both activity and awe into consideration.

2. Which of the following best explains “disquietude” underlined in Paragraph 3?

A．desire

B．anxiety

C．discomfort

D．contentment

3. Why are the findings regarded as subjective?

A．The number of volunteers is small.

B．The awe emotion is hard to measure.

C．The daily assessments are difficult to complete.

D．The period of the experiment isn’t long enough.

4. What is the attitude of Dr. Sturm to “awe walks”?

A．Skeptical.

B．Indifferent.

C．Supportive.

D．Critical.