选择知识点

There's something satisfying about volunteering. Studies have shown that volunteering helps people who donate their time feel more socially connected, thus warding off loneliness and depression. But a growing body of evidence suggests that people who give their time to others might also be rewarded with better physical health, including lower blood pressure and a longer lifespan.
  Evidence of volunteerism's physical effects can be found in a recent study from Carnegie Mellon University, published this month in Psychology and Aging. Adults over age 50 who volunteered on a regular basis were less likely to develop high blood pressure than non-volunteers. High blood pressure is an important indicator of health because it contributes to heart disease, stroke, and premature death.
  It's impossible for this study to prove that volunteering was directly responsible for the lower blood pressure. People who volunteer may be more likely to do other things, like eating a healthy diet or exercise, which lower blood pressure. But the results are in line with other findings on the topic.
  How might volunteering contribute to lower blood pressure？Performing volunteer work could increase physical activity among people who aren't otherwise very active, says leading study author Rodlescia Sneed, a doctoral candidate in social and health psychology at Carnegie Mellon University. It may also reduce stress. "Many people find volunteer work helpful with respect to stress reduction, and we know that stress is very strongly linked to health out-comes," she says.
  A 2012 study in the journal Health Psychology found that participants who volunteered with some regularity lived longer, but only if their intentions were truly altruistic（无私心的）． In other words, they had to be volunteering to help others-not to make themselves feel better.
  The Greek philosopher Aristotle once guessed that the essence of life is "To serve others and do good." If recent research is any indication, serving others might also be the essence of good health.



Which can replace the underlined phrase "warding off" in paragraph 1？ ______

A. getting rid of.
B. keeping up with.
C. running out of.
D. putting up with.

Why does the author mention the study from Carnegie Mellon University？ ______

A. To prove the benefit of volunteering to health.
B. To find out volunteerism's physical effects on heart.
C. To explain the connection between exercise and health.
D. To warn readers the danger of volunteering to blood pressure.

What can we learn from what Rodlescia Sneed said？ ______

A. Volunteers are supposed to be more outgoing.
B. Volunteer work can make people lack sports.
C. Taking appropriate exercise can strengthen social connection.
D. Performing volunteer work contributes to reducing stress.

What's the text mainly about？ ______

A. Volunteering can lower blood pressure.
B. Volunteering is beneficial to mental health.
C. Volunteering may be good for body and mind.
D. Volunteering can avoid suffering from heart disease.

There are many reasons why people can't get a good night's sleep and as with any other health conditions, things are not likely to improve until you find a way to break the cycle.
  These are some of the main factors that need to be addressed.
  Worry and stress
  We have all been kept awake by many factors that cause worry and stress in our lives. Money problems, relationship issues and work stresses can have you sitting up all night. A useful habit is to download your thoughts at the end of the day. Keep a pen and paper next to your bed and before you go to sleep, write down your thought and worries, create a to-do list for the following day or set down solutions and ideas that relate to work.
Diet and eating patterns
What and when you eat can have a major impact on your ability to sleep. Eating too late or indulging in a rich or spicy meal can keep you awake. These foods take a long while to digest and the after effects of indigestion and heartburn are not going to set you up well for a good quality sleep.
  A research suggests that both calcium and magnesium may be linked to poor sleep. Even low intakes of magnesium found in green vegetables, beans, nuts and seeds have been shown to make it harder to stay asleep. Calcium is found in dairy foods, soybeans and green vegetables and low levels have also been shown to make it more difficult to nod off.
  Alcohol and caffeine
  Tea, coffee and energy drinks contain caffeine that helps to stimulate the nervous system and make you more alert, which is great if you need a pick-me-up. Dosing up on caffeine during the day can affect your ability to sleep later on in the evening. Try limiting your intake of caffeine to the morning and switch to decaffeinated options such as herbal teas. Alcohol is a double-edged sword when it comes to sleep. While a little may help to induce slumber, even in small amounts it can cause fragmented sleep patterns.
  Bedroom environment
"Your bedroom should be dark once the lights are switched off because melatonin, a sleep-regulating hormone, is very light-sensitive. Maintaining the right temperature can also help with sleep as a room that is too hot may prevent your core temperature from going down, which is essential for switching on the sleep mechanism within the body.



Which of the following is TRUE according to the passage？ ______

A. Melatonin is a chemical in our bodies that disturbs our sleep.
B. The lower the temperature is, the easier you will find it to sleep.
C. Drinking a little coffee in the morning may not affect your sleep at night.
D. You should eat more vegetables and wholegrains for supper to get a better sleep.

The passage can be found in the column of ______ in a newspaper.

A. Science
B. Health
C. Fashion
D. Education

Blue light before bedtime can make it harder to sleep, and the screens on phones, computers and televisions give out plenty of blue light. This is all true. But if you consider blue light as a major problem affecting your sleep or your eye health, it's time to change your mind.
  Philip Yuhas, a professor of optometry（验光）， writes at The Conversation, "Blue light isn't a uniquely technological evil. It's part of sunlight, and your eyes are exposed to plenty of it all the time. You're fine." The pigments （色素） and the lenses of our eyes actually block blue light fairly well-so in a sense, we already have built-in blue-blocking protection.
  Adding more protection isn't likely to help, though. You can buy glasses and screen filters（过滤器） that block blue light, but Yuhas points out they are probably a waste of money. He says,"The products that my patients ask about do not block out much blue light." The leading blue-blocking anti-reflective coating, for example, blocks only about 15% of the blue light that screens give out.
  You could get the same reduction just by holding your phone another inch from your face. Try it now and see if you notice a difference. No？ Then it shouldn't surprise you that a recent analysis concluded that blue-blocking glasses and coatings have no significant effect on sleep quality, comfort at the computer or retinal（视网膜的） health.
  The American Academy of Ophthalmology doesn't recommend blue-blocking products, either. Instead, if you're concerned about your eye health or your ability to get into sleep on time, you already know what to do： Put the screens away at bedtime. Read a book or find something else to do. While you're using screens, take a 20-second break every 20 minutes to look at something 20 feet away. If you get dry eyes when you look at screens for a long time, use artificial tears.



What do we know about blue light？ ______

A. It produces kinds of pigments.
B. It does serious harm to our health.
C. It can be blocked by our eyes effectively.
D. It is a unique product of electronics.

What can be learned about blue-blocking glasses from the text？ ______

A. They are widely popular.
B. They are almost useless.
C. They are inaccessible.
D. They are reliable.

What does the author suggest readers do？ ______

A. Try to wet dry eyes with tears.
B. Keep a distance from blue light.
C. Stop using screens in the evening.
D. Have regular breaks when using screens.

Which of the following would be the best title for the text？ ______

A. Does blue light really affect your health？
B. Are blue-blocking products recommended？
C. Where does blue light actually come from？
D. How can we avoid the harm from blue light？

Environmental groups and rock climbers are always at loggerheads because of the effect of rock climbing on the environment. There have been many examples, wherein rock climbers are accused of going into natural reserves and treating the animals, plants and rocks there badly. However, with the changing times, rock climbers are conscious and carry out minimal climbing.
  Rock climbers hammer bolts（螺栓） on climbing routes and in the process damage the nature of rocks. In addition, climbing activities also have an effect on the animals and plants situated near the climbing area.The plants growing near the base of rocks are trampled（踩踏），and the animals living in the climbing area are forced out of their places, whenever humans are around. For example, during the summer climbing season, pregnant females of an endangered species of snake live in open areas like roadsides, exposed walls or rocks, where there is less canopy closure（树冠郁闭） compared to areas occupied by non-pregnant females and males. According to climbers, these open areas are very ft for climbing during summer.
  Many rock climbers have understood the significance of wildlife plant and animal preservation and related issues, and therefore take measures to reduce effects on climbing areas. Considering the effect of climbing activities on natural reserves, various national parks and wildlife agencies have put forth certain regulations on climbers. There are seasonal closures of climbing areas to avoid illegal entrance of uninformed rock climbers.
  Climbers are always expected to support wilderness preservation Many environmental organizations have been formed to protect the environment and in the process draw up certain guidelines for rock climbers. Both sides have come to a common understanding of the effect of rock climbers on protected areas.



What does the underlined part "at loggerheads" in Paragraph 1 mean？ ______

A. In support.
B. In difficulty.
C. In disagreement.
D. In communication.

Why is the example of snakes mentioned in Paragraph 2？ ______

A. To show how special their living habits are.
B. To show rock climbing affects their lives.
C. To show climbers are exposed to great danger.
D. To show how to avoid wild animals in summer.

What do environmental organizations do to preserve wilderness？ ______

A. Give guidelines to rock climbers.
B. Accuse climbers of their climbing.
C. Close some secured natural reserves.
D. Encourage climbers to choose open areas.

What is the text mainly about？ ______

A. Efforts made to protect rock climbers.
B. The recent popularity of rock climbing.
C. Environmental issues of rock climbing.
D. Rock climbers' environmental awareness.

This may look like an ordinary plastic straw （吸管），but it is not made of plastic. Cameron Ross started the Celise Bio-products company, to produce single-use plastic alternatives from plant materials like these. They are made of poly lactic acid（聚乳酸）known as PLA from com starches （淀粉）．
  Cameron Ross said, "We work with food service providers, mainly larger brands, to help them get quality sustainable and cost-effective solutions, made from plants to start getting rid of single-use plastics." Single-use plastics such as bottles or straws are major cause of pollution. When we throw these away, they end up in a landfill or in the water like rivers. According to researchers, it could take up to more than 500 years for them to properly break down.
  Ross says he wasn't always so environmentally conscious himself. But ever since the hiking trip in West Virginia, when he spent more time picking up trash than enjoying nature, his priorities changed. That meant making biodegradable products that can break down in only a few years.
  While many cafes and restaurants are choosing paper products to be more eco-conscious, it isn't cheap. Paper straws can cost about eight times more than plastic straws. But bio-plastic straws cost less than a penny a straw, not even double the price of plastic ones.
  Another problem with paper straws is that they get soft and wet. You don't want to be sipping （啜饮）something that alters your drink, or starts to melt while you're drinking and then you have to get another paper straw, which creates more wastes than needed. Ross hopes his Washington DC-based company will provide an eco-friendly solution for food service providers.



Which aspect is NOT the focus of the Celise Bio-products？ ______

A. Material.
B. Appearance.
C. Quality.
D. Cost

What inspired Ross to start the Bio-products company？ ______

A. High profits.
B. Requests from food service providers.
C. Lower cost.
D. His changed environmental awareness.

What can we learn about the new straws？ ______

A. They are widely used in cafes and restaurants.
B. They cost less than paper ones.
C. They may soften or even melt while carrying water.
D. They produce more waste.

What's the author's purpose of writing the passage？ ______

A. To persuade more food service providers to work with Ross.
B. To explain the development of straws.
C. To introduce a new eco-friendly straw.
D. To compare different straws.

Great Activities for Nature Lovers   Hiking
  One of the easiest and most accessible ways to get close to nature is by setting out on a good old fashioned hike. Hiking generally doesn't require any fancy equipment or special skills, just a piece of map and a thirst for adventure. This activity can be as relaxing as you make it.
  Backcountry Camping
  Why limit yourself to just a day hike when you can have a full weekend （or longer） adventure？ Backcountry camping involves packing your tent, sleeping gear, food, and water on your back to set up camp in a remote location. If you're an experienced hiker and camper, this is an excellent way to test your survival skills and explore the wilderness.
  Mountain and Road Biking
  Unlike long hikes through the woods, biking allows you to cover more ground and travel farther in nature. Mountain biking typically involves riding up and down steep slopes, between trees, and over rocks. If this sounds too intense or your tires aren't suited for rugged terrain, consider taking a road bike on paved trails through forest preserves or along country roads.
  Gardening
  Contrary to popular belief, you don't have to travel beyond your own backyard to experience the beauty of nature every day. If your personality is less adventurous or your mobility restricted, consider planting a garden to grow your own vegetables, fruits, herbs, or flowers. There's something truly satisfying about mixing up a salad with fresh ingredients you grew yourself. One of the best parts about spending time in nature is that it doesn't have to break your budget and anyone can do it.



What does hiking need for hikers？ ______

A. A world map.
B. A strong desire.
C. Practical skills.
D. Necessary equipment.

Where will you go to show your survival potential in the wild？ ______

A. To a backyard.
B. To a forest.
C. To a mountain.
D. To a distant place.

Which of the following can take you to travel farthest？ ______

A. Hiking.
B. Backcountry Camping.
C. Gardening.
D. Mountain and Road Biking.

Every year, little black-and-white birds called pied flycatchers（斑姬鹟） travel from sub-Saharan Africa to northern Europe to feast on caterpillars （毛毛虫）， claim a nest, and have babies. And they fly back a few months later. But recently, some flycatchers have arrived only to find their nesting sites occupied by great tits （大山雀）． And those birds don't just chase flycatchers away-they attack them, kill them, and eat their brains.
  Great tits live in European forests all year round. Flycatchers are regular vacationers. Since the 1980s,  flycatchers' reproductive season has been inching up earlier in the month of April. Warm spring temperatures have caused caterpillar populations to boom. To adapt to that, flycatchers arrive a bit earlier, too. That won't be too big a problem. But now, tits delay their breeding period a bit in April, so they overlap with the flycatchers, and violence begins.
  Moreover, there's limited nesting space in many of these birds' favorite forests-the trees can be quite young and have very few tree holes where birds can nest. Volunteers and academics have placed nestboxes to help. But with climate change, birds' breeding schedules getting closer, there aren't enough nestboxes to go around. Unfriendly hosts-the tits, eat their brains.
  "Great tits are superior competitors when it comes down to a fight, " said Jelmer Samplonius, lead author of a study. "People see it as a cute garden bird, but some of them have a real anger management problem. " Luckily, the murdered birds were often surplus males that arrive late. The deaths haven't had a big impact on the population because those late males probably won't have had babies anyway. But there's always the chance that it could get worse.
  "Whatever the flycatcher population's future may hold, " Samplonius said, "this is a good example of why it's essential to study how climate change can shift animals' schedules, often with deadly consequences. Understanding different responses to changing environments will be an important part of species assessments in coming years."



What has happened to pied flycatchers recently？ ______

A. They couldn't get enough food.
B. Their nesting sites were destroyed.
C. Their babies have become less likely to survive.
D. Their lives have been threatened by another kind of birds.

Which is one of the causes of the violence between pied flycatchers and great tits？ ______

A. The change in migration of flycatchers.
B. The delay of flycatchers' reproductive season.
C. The reduction of both birds' favorite forests.
D. The two birds' sharing the same food.

Which can best describe great tits？ ______

A. Ugly.
B. Smart.
C. Aggressive.
D. Lazy.

What can be the best title for the text？ ______

A. A terrible bird murder
B. Birds' struggle to hunt
C. Birds' influence on climate change
D. The future of mixed species communities

Nowadays medical technology seems to be advanced enough for doctors to perform brain transplants （移植）．Though this procedure has only been successfully performed on animals so far, doctors are still hoping to perform this procedure on humans. However, in my opinion, brain transplants should not be performed at all, especially not on humans because of the large number of problems and side effects that could come along with. Hopefully these dangerous side effects will convince doctors not to perform this procedure on humans.
  Despite many benefits technology brings, I do not think this medical technology of brain transplants will help. We were all born with one brain and through childhood to adolescence our mind developed into who we are, so if with a different brain we would no longer be unique. A person with a different brain would seem to be a total stranger and in many ways they would be. No one should steal our identity from us, even if we are seriously injured, and change it to a completely new one. Also for the people who have died with healthy brains, that was their identity and it should not be given to anyone else.
  Another problem with brain transplants is how doctors can choose what are "healthy" or "normal" brains. An elderly person who has died would have an aged brain that would not be as efficient as a younger person's brain. Then would doctors have to find healthy brains of the same age as the person who needs it？ This could also bring up other factors such as intelligence, gender, or physical problems that a person might have had before death. Also another problem might be how long a brain can be kept "alive" after death and how it can be kept "alive" without damage.
  Overall, my feelings about this surgery are that it should not be done on humans until doctors have overcome all the problems and obstacles （障碍） that stand in their way of making human brain transplants successful.



Why does the author think brain transplants should not be performed at all？ ______

A. The cost of the surgery is extremely high.
B. Doctors are not able to perform brain transplants.
C. A good many problems and side effects may arise.
D. This procedure has only been successful on animals.

What is the second paragraph mainly about？ ______

A. People shouldn't give their healthy brains to others.
B. Having a brain transplant means losing one's identity.
C. Transplanting brains is changing old brains into new ones.
D. Having brain transplants indicates stealing identity from others.

What do we know about "healthy" brains？ ______

A. Aged brains aren't healthy brains.
B. Young brains are always healthy.
C. Healthy brains cannot be kept "alive"．
D. It's very difficult to tell healthy brains.

What is the author's purpose in writing the passage？ ______

A. To encourage brain donation.
B. To stress the importance of brain operation.
C. To argue against brain transplants on humans.
D. To introduce the technology of brain transplants.

If you're looking for a reason to care about tree loss, this summer's record-breaking heat waves might be it. Trees can lower summer daytime temperatures by as much as 10 degrees Fahrenheit（华氏度）， according to a recent study. But tree cover in US cities is shrinking. A study published last year by the US Forest Service found that we lost 36 million trees annually from urban and rural communities over a five-year period. If we continue on this path, "cities will become warmer, more polluted and generally more unhealthy for inhabitants," said David Nowak, a senior US Forest Service scientist and co-author of the study. Nowak says there are many reasons our tree cover is declining, including hurricanes, tornadoes, fires, insects and disease. But the one reason for tree loss that humans can control is sensible development.
  "We see the tree cover being changed, which means when we look at the photographs, what was there is now replaced with a parking lot or a building," Nowak said. "Every time we put a road down, we put a building and we cut a tree or add a tree, it not only affects that site, it affects the region." The study placed a value on tree loss based on trees' role in air pollution removal and energy conservation.
  Nowak says there's a downside to trees too, such as pollen allergies or large falling branches in storms, "and people don't like sweeping leaves." But, he says, there are ways cities and counties can manage trees to help communities thrive. Urban forests especially need our help to replace fallen trees. Unlike rural areas, it is very difficult for trees to repopulate themselves in a city environment with so much pavement and asphalt（沥青）． "A lot of our native trees can't actually find a place to drop a seed so they can regenerate," explains Greg Levine, co-executive director for Trees Atlanta. "That's why the community has to go in and actually plant a tree because the areas just aren't natural anymore."
  Nowak says the first step is caring for the trees on your own property. "We think we pay for our house, and so we must maintain it. But because we don't pay for nature, we don't need to. And that's not necessarily true."



Why does the author mention "trees can lower summer daytime temperatures"？ ______

A. To tell the temperatures in summer are high.
B. To introduce the topic.
C. To tell trees are helpful.
D. To explain the reason of tree loss.

How can humans control tree loss according to Nowak？ ______

A. Improve climate to let trees grow.
B. Prevent fires form damaging trees.
C. Develop cities in reasonable ways.
D. Decrease insects in citites.

Why forests in cities need our help？ ______

A. Because trees in urban areas can't regenerate naturally.
B. Because native trees don't drop seeds any more.
C. Because trees don't grow in a city environment.
D. Because humans want to plant more trees.

What is the purpose of this passage？ ______

A. Describe the importance of trees in cities.
B. Show the number of trees in the US is declining.
C. Ask people to plant trees with the author.
D. Appeal people to protect trees in their surroundings.

Running may feel like a big task for most of us. But do you know our species has evolved to run better than any other animals on this planet？ Cheetahs are the fastest land animals in the world. But do you know that humans can leave them in the dust？ At least, in the long run, that's right. When it comes to endurance, we can outrun cheetahs, wolves and even horses. So what makes humans such endurance running superstars？ The secret weapon is our sweat. We have 2-4 million sweat glands（腺） all over our body, which means we can run and cool ourselves at the same time. Having no fur is also a huge plus. In contrast, dogs rely on panting（喘息） to cool down, and other animals, like horses and camels, also sweat, but less effectively. As a result, they overheat faster and must slow down sooner.
  So, why did humans get to be such great endurance runners, anyway？ Some experts believe this became important around 2-3 million years ago, when we started hunting. Because we couldn't chase down a gazelle（瞪羚） like a cheetah, early humans learned hunting.
  Studies show running can lower body weight and body fat. And the longer you train, the greater the benefits are. Just one year of training has been shown to reduce body weight by about 7 lbs, lower body fat by 2.7% and decrease resting heart rate by 2.7%．
  It may seem really hard, or even impossible to run a mile or a marathon. But in fact, you were born to go on that run. We all were.



In the first paragraph, cheetahs are mentioned to ______ ．

A. show cheetahs are the fastest land animals in the world
B. introduce humans can run fastest on the planet in the long run
C. contrast with wolves and even horses in one aspect of endurance
D. inform running may be a big challenge for most of us humans

Why can we humans be endurance running superstars？ ______

A. We can pant to cool down our heat like dogs.
B. We can sweat effectively like horses and camels.
C. We have massive sweat glands and meanwhile no fur.
D. We can run and overheat fastest to cool down ourselves.

According to studies in the text, if you want to lose weight, what should you do？ ______

A. Eat a variety of vegetables and less fat.
B. Work out at the gym every day.
C. Exercise outside as much as you like.
D. Conduct systematic training in running.

What does the author intend to emphasize in the last paragraph？ ______

A. Humans have great running ability by birth.
B. Humans can chase down animals like cheetahs.
C. Marathoners don't need hard training.
D. Running can lower body weight and fat.