【推荐2】Here’s a new warning from health experts: sitting is deadly. Scientists are increasingly warning that sitting for long periods, even if you exercise regularly, could be bad for your health. And it doesn't matter where the sitting takes place--in the office, at school, in the car or before a computer or TV. Just the overall number of hours it takes matters. Several studies suggest people who spend most of their days sitting are more likely to be fat, have a heart attack or even die. While health officials have issued(发布) guidelines advising on the least amounts of physical activities, they haven’t suggested people try to limit how much time they spend in a seated position.
“After four hours of sitting, the body starts to send harmful signals,” said Ekblom-Bak of the Swedish School of Sport and Health Sciences. She explained that genes controlling the amount of glucose(葡萄糖) and fat in the body start to shut down.
Even for people who exercise, spending long periods of time sitting at a desk is still harmful. Tim Armstrong, a physical activity expert at the World Health Organization, said people who exercise every day but still spend a lot of time sitting might get more benefits if that exercise were spread across the day, rather than in a single hour.
Still in a study that tracked more than 17,000 Canadians for about a dozen years, researchers found people who sat more had a higher death risk, whether they exercised or not. Experts said more research is needed to figure out just how much sitting is dangerous, and what might be possible to offset those effects.
People should keep exercising because that has a lot of benefits,” Ekblom-Bak said. “And when they’re in the office, they should try to interrupt sitting as often as possible.”
1. The underlined word “offset" in Paragraph 6 most probably means_______.

A．get rid of	B．make use of
C．work out	D．turn to

2. Sitting too much is dangerous because it can________ .

A．increase glucose and fat in the body

B．make a person become lazy

C．destroy the balance of glucose and fat in the body

D．make a person unable to exercise enough in a day

3. In the opinion of Ekblom-Bak, when at work, you’d better have a rest by_______ .

A．taking a walk around your office

B．chatting online or playing computer games

C．sending your friends emails

D．listening to music while sitting

4. Which of the following might be the best title for the passage?

A．More and More People Sit Too Much

B．Side Effects of Sitting Too Much

C．Don’t Sit Too Much While Working

D．Sitting Too Much Could Be Dangerous

【推荐1】Summer brings flowers and dirt and barbeque smoke. In the most wintery places, there isn’t much outside on cold days except snow, strong wind and cars warming up. Pine needles(松针), wood smoke and snow—these are the smells of winter, and for people who live with different seasons, wintery weather brings its own set of olfactory(嗅觉的) experiences. But why does the cold of winter smell different from the heat of summer?

One reason is that odor molecules(气味分子) move much more slowly as the air temperature drops, said Pamela Dalton, an olfactory scientist at the Monell Chemical Senses Center in Philadelphia. That means that there are simply fewer smells to smell on a cold, crisp day than there are on a hot and humid one. It’s the same reason why hot soup smells more than cold soup does and why the garbage truck leaves behind the strongest smells on steamy summer days.

What’s more, our noses don’t work quite well when the surrounding air is cold, Dalton said. In experiments that require biopsies(活组织检查) of olfactory receptors that lie deep inside the nose, researchers at Monell have discovered that the receptors “bury themselves a little more deeply in the nose in winter,” she said, “possibly as a protective response against cold, dry air.”

“There is a strong psychological factor in our sense of smell,” Alan Hirsch, a neurologist and psychiatrist in Chicago, added, “and what we expect to smell has a big influence on what we actually smell.” In The Invalid’s Story by Mark Twain, for example, a man is stuck on a train next to what he thinks is a rotting(腐烂的) dead body but is actually a box of cheese that smells extremely unpleasant. So strongly affected by the smell, he spends too long looking for fresh air on the freezing platform and develops a fever that ends up killing him. “What you think of a smell will have powerful effects on you whether you like it or whatever you think it to be,” Hirsch said. “So, if you go outside in winter and you are used to smelling snow or nuts in the fire or whatever you happen to smell outside, that’s what you will interpret smells to be.”

To cope with lack of smells in winter, many people try to burn more candles with pleasant smells, cook more sweet stews(炖菜)and bake more cookies, which creates a greater contrast between indoor and outdoor environments. “You’re probably fond of indoor smells in winter,” Dalton said. “Doors are closed, and windows are closed. We concentrate on the smells of cooking and living.”

1. According to the second paragraph, Pamela Dalton will probably agree that ____.

A．there are not many smells available to be smelled in winter

B．hot soup is more popular with people in winter than cold soup

C．garbage truck is easier to break down in cold winter

D．air temperature affects the direction in which smells spread greatly

2. The author used the story written by Mark Twain to show that ______.

A．one can easily feel terrible smells in a small space

B．no one can survive when there is lack of fresh air

C．one’s mind and thoughts can affect his sense of smell

D．one’s opinion on smells is quite different from others’

3. Which of the following is NOT a measure people take to deal with lack of smells in winter?

A．Closing windows.	B．Cooking stews.
C．Burning candles.	D．Baking cookies.

4. How is the passage organized?
(P: Paragraph)

A．	B．
C．	D．

【推荐1】More than one billion people currently live in environments where water is in short supply, making water one of the most highly prized natural resources. Scientists are always searching for ways to increase access to this valuable resource. They may have found a solution in an unlikely area: one of the driest places on Earth.

The Namib desert in Africa is one of the world’s driest places, while Namib beetle is a unique organism that grows in this environment because of its amazing physical adaptation. The wings on the Namib beetle are filled with bumps and grooves(槽) that help it collect water from the air. The top of each bump is smooth like glass and attracts water. But the slopes of each bump and the grooves in between the bumps have waxy (带蜡的) surfaces that repel water . Each time the fog occurs, the beetle positions its body at a 45-degree angle to the wind. As the wind pushes the fog across the desert, each bump on the beetle’s back collects water. When enough moisture has been collected from the fog, a drop rolls off the bumps into the waxy grooves and then into the mouth of the beetle.

Scientists are using the Namib beetle’s wing design as a guide for creating their own water-collection surfaces. They have inserted dozens of glass globes into thin layers of wax. Similar to the bumps and grooves on the wings of the beetle, the smooth glass bubbles collect water, while the wax repels it. By placing the glass-and­wax panels in environments with high-moisture air, the scientists think they will be able to collect water.

The Namib beetle’s wing design may also provide unexpected solutions to other problems. In areas where thick fog causes chaos, panels of these water-gathering surfaces may be able to remove the fog. This could potentially reduce travel delays at airports and prevent fog-related accidents on roadways. It seems that studying this little beetle may lead to a variety of benefits for humans.

1. What will the Namib beetle do when fog appears in the desert?

A．It will release a waxy substance to cover its back.

B．It will place its body in a particular way to collect water.

C．It will create bumps and grooves on its wings.

D．It will open its mouth to drink the water in the air.

2. The author focuses on a unique feature of the Namib beetle in order to highlight how the beetle ________________.

A．could serve as a source of water for desert travelers

B．struggles to survive in the dry part of the world

C．uses its wings to stay cool in a dry environment

D．is able to get access to water in the absence of rain

3. What’s the writing purpose of this passage?

A．To prove that water can be obtained from moist air.

B．To explain how the Namib beetle adapts to living in a hostile environment.

C．To show how people can apply designs from nature to create solutions to global problems.

D．To stress that water is a valuable resource in many areas on Earth.

【推荐2】A new research, presented on Monday, suggests that parents who go down slides with their kids are actually making slides even riskier for their little ones.

Led by Dr. Charles Jennissen, a professor at the University of Iowa, the research found that placing children (especially infants and toddlers蹒跚学步的小孩) on adult laps increases the risk of injury to their lower legs, including broken bones.

"I've seen a lot of these injuries all through my career, and I hadn't seen anybody talk about this problem," says Jennissen.

So Jennissen and his colleagues found that about 350,000 children under the age of six were injured on slides in the U.S. from 2002 to 2015. Injuries were most common among kids from 12-23 months of age, and the most common injury was lower leg fractures (骨折).

The researchers found that 94 percent of 600 cases include lower leg injuries. This is important, because that's not how a kid falling off a slide alone would usually get hurt. The fact that so many kids are getting lower leg injuries—and that those injuries seem to get less common as kids get older—suggests something else is at play.

Jennissen thinks that when children are sliding alone, they aren’t going fast enough or carrying enough body weight to hurt themselves. When they’re sitting on an adult’s lap and their foot gets caught, they have the added momentum of an adult body.

"We think a lot of these lower extremity injuries are because they're on the lap," says Jennissen. "We don't know that for sure, because no parents say that. But from my experience, and the data that suggests it, we think almost all of these are kids are on the lap."

Jennissen isn’t arguing that you should never go down the slide with your kid—he agrees that it’s fun and that he’s done it with his own kids—but he thinks adults should realize the risks.

1. What can we learn about the research from the passage?

A．Many parents are hurt when going down slides with their kids.

B．More and more adult laps are found hurt in the accidents.

C．The research issue has not yet concerned many people.

D．Many people have discussed the possible reasons for the injuries.

2. The underlined phrase “at play” in Para.5 probably means _____.

A．paying attention

B．taking effect

C．solving problems

D．making efforts

3. What is Jennissen’s attitude towards parents’ going down slides with kids?

A．He supports it.	B．He is against it.
C．He doesn’t care about it.	D．He is careful about it.

【推荐1】When John was growing up, other kids felt sorry for him. His parents always had him weeding the garden，carrying out the garbage and delivering newspapers. But when John reached adulthood, he was better off than his childhood playmates. He had more job satisfaction, a better marriage and was healthier. Most of all, he was happier.Far happier.

These are the findings of a 40­year study that followed the lives of 456 teenage boys from Boston. The study showed that those who had worked as boys enjoyed happier and more productive lives than those who had not. “Boys who worked in the home or community gained competence (能力) and came to feel they were worthwhile members of society，”said George Vaillant, the psychologist (心理学家) who made the discovery. “And because they felt good about themselves, others felt good about them.”

Vaillant's study followed these males in great detail. Interviews were repeated at ages 25, 31 and 47. Under Vaillant, the researchers compared the men's mental­health scores with their boyhood ­activity scores. Points were awarded for part­time jobs, housework, effort in school，and ability to deal with problems.

The link between what the men had done as boys and how they turned out as adults was surprisingly sharp．Those who had done the most boyhood activities were twice as likely to have warm relations with a wide variety of people，five times as likely to be well paid and 16 times less likely to have been unemployed. The researchers also found that IQ and family social and economic class made no real difference in how the boys turned out.

Working—at any age—is important.Childhood activities help a child develop responsibility, independence, confidence and competence—the underpinnings (基础) of emotional health. They also help him understand that people must cooperate and work toward common goals. The most competent adults are those who know how to do this.Yet work isn't everything. As Tolstoy once said，“One can live magnificently in this world if one knows how to work and how to love, to work for the person one loves and to love one's work.”

1. What do we know about John?

A．He enjoyed his career and marriage.

B．He had few childhood playmates.

C．He received little love from his family.

D．He was envied by others in his childhood.

2. Vaillant's words in Paragraph 2 serve as ________．

A．a description of personal values and social values

B．an analysis of how work was related to competence

C．an example for parents' expectations of their children

D．an explanation why some boys grew into happy men

3. Vaillant's team obtained their findings by ________．

A．recording the boys' effort in school

B．evaluating the men's mental health

C．comparing different sets of scores

D．measuring the men's problem solving ability

4. What does the underlined word “sharp” probably mean in Paragraph 4?

A．Quick to react.	B．Having a thin edge.
C．Clear and definite.	D．Sudden and rapid.

【推荐2】Humans may have been enjoying cacao, which has been used to make chocolate, for much longer than experts had thought.

Researchers at the University of British Columbia in Canada have found that humans grew cacao trees and consumed (食用) cacao starting around 5,300 years ago.

The researchers found evidence of cacao’s use at an ancient village in the highlands of southeastern Ecuador. They examined the remains of very old objects. The village was part of the Mayo-Chinchipe culture of the Andes.

Scientists had already mostly agreed that cacao was first domesticated in South America instead of Central America, as they once believed. But the new discovery shows cacao was grown about 1,500 years earlier than was known before.

The University of British Columbia researchers also identified (证实) a substance found in the cacao tree but not in its wild relatives. This suggests that humans grew the tree for food purposes.

Today, the seeds are cooked and turned into many chocolate products.   But thousands of years ago, cacao was used to make drinks.

Michael Blake is a professor of University of British Columbia who helped lead the study. He said that the objects on which cacao was found suggest a lot about how people used the substance at the time.

“They clearly drank it,” Blake told the Reuters news service.

There is no clear history of native populations in South or Central America using cacao to make chocolate the way people do now, the researchers reported. Native populations in the upper Amazon area today still use cacao to make special drinks, they added.

Evidence suggests cacao growing moved into Central America and Mexico about 4,000 years ago. It is not clear how cacao’s use spread between South and Central America.

But by the time Spanish explorers arrived in Central America in the late 1400s, people were using it to make hot and cold chocolate drinks with spices.

By the 1580s, Spain began importing cacao and spreading it to other European countries. By the 1800s, technology developed in the Netherlands made it possible to turn cacao into a solid chocolate product.

1. Where was cacao grown earliest?

A．Mexico.	B．Canada
C．Central America.	D．South America.

2. When it comes to the introduction of cacao to Europe, which country contributed most?

A．America.	B．Canada.
C．Spain.	D．Netherland.

3. Which of the following can serve as a best possible title for this passage?

A．The history of cacao.	B．The home of cacao.
C．The use of cacao.	D．The spreading or cacao.

【推荐3】Grandparents are respected in many human societies. But telling stories about old times and overfeeding grandchildren seem like human qualities. Are these classic grandparent behaviors really limited to humans？

Do any animals know their grandparents the way people do?

For most species on Earth，the answer is certainly “No”. "Usually，there aren't grandparents around anymore when an animal is born，"said Mirkka Lahdenpera，a biologist at the University of Turku in Finland. "Even if an animal's life span does overlap（重叠）with its grandparents'，most species spread out to avoid competing for resources，so the chance of running into a grandparent is slim. "

But there are a few clear exceptions，primarily among mammals（哺乳动物）that live in close social groups. In troops of langur monkeys in India，older females lived together with their daughters and grandchildren. The grandmother langurs defend the group's babies against attacks and even give their own grandchildren special treatment.

Many whale species，too，travel in family groups that include both grandmothers and grandchildren.

Elephant herds are also famously matriarchal. They are led by a grandmother，who can live to around 80 years old，and are generally made up of her daughters and their young. The females in a herd form close bonds and work together to raise their young.

Lahdenper found that the babies of young mothers were eight times more likely to survive if their grandmothers lived near them than if they didn't. When the young mothers were older and more experienced at raising babies，this beneficial grandmother effect disappeared even if the actual grandmothers were still around.

Indeed，most evidence for the benefits of grand parenting comes from mammals. But in 2010，researchers found that in troops of insects called gall-forming aphids，older females defend their relatives after they've stopped reproducing（繁殖）.

And what about grandfathers？Studies of humans in recent decades have shown that a living grandfather can improve a person's mental health and other indicators of well-being. But there's no evidence of that in the animal kingdom. Male animals rarely socialize with their own children，let alone any grandchildren.

1. From what Mirkka Lahdenpera said, we can learn that___________.

A．an animal is not very likely to meet a grandparent

B．an animal is taken away from its grandparents at birth

C．animals' grandparents move away to avoid responsibility

D．animals' grandparents often fail in competition for resources

2. The underlined sentence in Paragraph 5 indicates that._________.

A．elephants have a high level of intelligence

B．elephants enjoy an equal and fair social system

C．elephants are the largest land animals with a long life

D．elephants live in social groups with females in charge

3. What can be inferred from the passage?

A．Insects still able to reproduce will defend their relatives.

B．Animals' beneficial grandmother effect will exist forever.

C．Animals can be mentally healthier with their grandfathers.

D．Male animals seldom spend time with their grandchildren.

4. Which of the following might be the best title of the passage?

A．Do any animals know their grandparents?

B．Do any animals respect their grandparents?

C．How do animals live with their grandparents?

D．How do animals socialize with their grandparents?