1 . Wisdom teeth seem like a biological mistake, leading to millions of surgeries per year. But for some people, these “extra” teeth come up just fine, while others don’t get them at all. What’s the biological story here?
According to the standard story, before surgical intervention, people with impacted wisdom teeth expired. Those lacking the problematic teeth increased in number, passing on genes for reduced numbers of teeth to future generations. Today, thanks to dental surgeons, individuals with impacted teeth survive and contribute to the gene pool.
But decades of research challenges this survival-of-the-toothless explanation. Many scholars now propose that wisdom teeth problems originate from our eating softer foods as children, made possible by farming and industrialization. Here’s the theory: Compared to wild resources consumed by hunter-gatherers, agricultural and processed foods are softer. Hard food during childhood seems to stimulate jaw growth, allowing mouths to grow large enough for more teeth. Soft food doesn’t require enough of a chewing workout to maximize jaw growth potential.
Around 12,000 years ago, humans began to experiment with farming, and this lifestyle ultimately took hold in most societies. Domesticated products, like wheat flour and cow’s milk, make for much softer diets than wild foods. What’s more, the industrialization of food production has really softened our meals. So the idea is that processed and/or agricultural diets reduce the stress on our jaws necessary to result in full growth when we reach early adulthood. By the time we’re reaching adulthood, there may not be enough space to accommodate our final molars (臼齿).
This theory is supported by research. For example, a 201l paper measured skulls housed in museums from six farming and five hunter-gatherer groups. The farmers, raised on softer foods, consistently had shorter jaws, which would have provided less space for tooth formation.
Consequently, many dental scientists recommend parents put some additional raw fruits, vegetables and nuts on kids’ plates, which could potentially prevent later wisdom teeth removals.
1. What does the underlined word “expired” in Paragraph 2 mean?| A．Suffered. | B．Complained. | C．Died. | D．Failed. |
| A．They tended to have very large jaws. |
| B．They hated food requiring a chewing workout. |
| C．They were often troubled by impacted wisdom teeth. |
| D．They believed in the survival-of-the-toothless theory. |
| A．Bring their kids to the dentist regularly. |
| B．Increase the number of hard foods in their kids’ diet. |
| C．Get more kids’ tooth formation knowledge. |
| D．Encourage their kids to eat more cooked vegetables. |
| A．What role do genes play in our tooth formation? |
| B．What can we do to accommodate our final molars? |
| C．Why do some people have reduced numbers of teeth? |
| D．Why do humans have wisdom teeth that need to be removed? |
2 . As time goes on, neuroscientists learn more about the wonders of human brains. The deeper understanding offers ways to enhance your brain to work in your favor. You don’t have to be a brain scientist to do it!
When you hear the word hack, you might be reminded of the snaky computer science term. Computer hackers need to understand the inner workings of a computer to break into its system.
Neurohackers use their knowledge of how the brain works to change though patterns, like daily habits. Doing this requires understanding the way habits form in the brain. Whenever you repeat a task, the brain connects its wires together between brain cells. Over time, these habits become hardwired into the brains.
Below the conscious mind lives the subconscious, a deeper mental space that hosts what you have previously engraved into your mind.
| A．Find out what neurohacking is. |
| B．The same goes for neurohackers. |
| C．Just learn how to hack your brain. |
| D．How can you improve your mindfulness? |
| E．How do you change those undesirable habits? |
| F．Habits free up our brains so that we can learn new things. |
| G．With proper practices, you’ll build a deeper awareness of your own brain. |
3 . When we see well, we do not think about our eyes very often. It is only when we cannot see perfectly that we realize how important our eyes are.
People who are near-sighted can only see things that are very close to their eyes. Everything else seems blurry(=unclear). Many people who do a lot of work, such as writing, reading and sewing become near—sighted.
People who are far-sighted suffer from just the opposite problem. They can see things that are far away, but they have difficulty in reading a book unless they hold it at arm’s length. If they want to do much reading ,they must get glasses, too.
Other people do not see clearly because their eyes are not exactly the right shape. They have what is called astigmatism (散光). This, too, can be corrected by glasses. Some people’s eyes become cloudy because of cataracts (白内障). Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.
Having two good eyes is important for judging distances. Each eye sees things from a slightly different angle. To prove this to yourself, look at an object our of one eye; then look at the same object out of your other eye. You will find the object’s relation to the background and other things around it has changed. The difference between these two different eye views helps us to judge how far away an object is. People who have only one eye cannot judge distance as people with two eyes.
1. We should take good care of our eyes ________.| A．only when we can see well |
| B．only when we cannot see perfectly |
| C．even if we can see well |
| D．only when we realize how important our eyes are |
| A．near-sighted | B．far-sighted |
| C．astigmatic | D．suffering from cataracts |
| A．seeing at night | B．seeing objects far away |
| C．looking over a wide area | D．judging distances |
| A．one eye bigger than the other |
| B．eyes that are not exactly the right shape |
| C．a difficulty that can be corrected by an operation |
| D．an eye difficulty that cannot be corrected by glasses |
4 . If you don't use it, you lose it. At least, that's how the old saying goes. It refers to the idea that something which does not get used regularly quickly falls into a state of decline. Muscles, for example, will waste away without use. In order to resist this, people take regular exercise to keep their skills sharp.
Well, what about the brain? As we age, our brains can naturally begin to decline. In some cases, this can lead to certain mental conditions such as dementia(痴呆)，which I'm sure you will agree, no one wants. However, all is not lost because these days it's relatively easy to train your brain. Smart phones and apps have put programmes into our hands that can test, maintain and even improve our memories, mathematical skills and a lot of other mental abilities. With a little practice every day, we can keep our brains nice and sharp, right?
Well, no, actually. According to a report from the Global Council on Brain Health, even though many people thought it was important to play online games, such as puzzles and mind games, which are designed to improve brain health, the evidence of the benefits was “weak to non-existent”.
There are other ways to promote the old grey matter. It recommends seeking out new activities that challenge the way you think and are socially engaging，while leading to a healthy lifestyle. Among their suggestions are practising tai chi, taking photography classes, learning new technologies, gardening, art projects or volunteering.
There's more good news, too, James Goodwin, chief scientist at Age UK has said that brain decline is not inevitable (不可避免的）. As long as the activities are “new to you and require your concentrated attention”, they can provide benefits for brain health. So, hurry up, get out there and try something new. Maybe it's time to try that hobby you've always wanted to do. And as for me? I'm off to learn the piano.
1. From which is the text probably taken?| A．A biology textbook. | B．A healthy magazine. |
| C．A travel brochure. | D．A research paper. |
| A．Making more shopping. | B．Avoid brain decline. |
| C．Doing exercises alone. | D．Going out with friends. |
| A．Trying something new. | B．Using smart phone regularly. |
| C．Playing games online. | D．Doing what you are good at. |
| A．Advantages of trying something new. |
| B．Disadvantages of using smart phones. |
| C．Ways to keep our brain as sharp as possible. |
| D．How to spend time meaningfully at an old age. |
5 . Eyesight plays a very important role in our daily life. Every waking moment, the eyes are working to see the world around us. Over forty percent of Americans worry about losing eyesight, but it's easy to include steps into our daily life to ensure healthy eyes. Here are five suggestions for a lifetime of healthy eyesight:
Schedule yearly exams.
Protect against UV rays .
Long-term stay in the sun creates risk to your eyes. No matter what the season is, it’s extremely important to wear sunglasses.
Two-thirds of Americans spend up to seven hours a day using computers or other digital products.
As part of a healthy diet, eat more fruits and vegetables each day. Vitamins C and E help protect eyesight and promote eye health.
Practice safe wear and care of contact lenses.
Many Americans use contact lenses to improve their eyesight. While some follow the medical guidance for wearing contact lenses, many are breaking the rules and putting their eyesight at risk.
Otherwise: you may have problems such as red eyes, pain in the eyes, or a more serious condition.
| A．Eat your greens. |
| B．Eye care should begin early in life. |
| C．They can properly protect your eyes. |
| D．Stay in good shape by taking more vitamins. |
| E．Parents usually don’t care about their own eyesight. |
| F．Always follow the doctor’s advice for appropriate wear. |
| G．This frequent eye activity increases the risk for eye tiredness. |
6 . Researchers continue to show the power behind our sense of smell. Recent studies have found, among other things, that the smell of foods like pizza can cause uncontrollable anger in drivers on roads.
The review explains that smell is unique in its effects on the brain. According to Conrad King, the researcher who carried out the review, "more than any other senses, the sense of smell goes through the logical part of the brain and acts on the systems concerned with feelings. This is why the smell of baking bread can destroy the best intentions of a dieter."
Smell, which dictates the unbelievable complexity of food tastes, has always been the least understood of our senses. Our noses are able to detect up to 10,000 distinct smells. Our ability to smell and taste this extremely large range of smells is controlled by something like 1,000 genes (基因), which make up an amazing 3% of the human genome. Researchers Richard Axel and Linda Buck were together awarded a Nobel Prize in 2004 for their ground-breaking research on the nature of this extraordinary sense. These two scientists were the first to describe the family of 1,000 olfactory (嗅觉) genes and to explain how our olfactory system works.
According to one study in the research review, smelling fresh pizza or even the packaging of fast foods can be enough to make drivers feel impatient with other road users. They are then more likely to speed and experience uncontrollable anger on roads. The most reasonable explanation is that these can all make drivers feel hungry, and therefore desperate to satisfy their appetites.
In contrast, the smells of peppermint and cinnamon were shown to improve concentration levels as well as reduce drivers’ impatience. Similarly, the smells of lemon and coffee appeared to promote clear thinking and mental focus.
However, the way genes regulate smell differs from person to person. A study by researchers in Israel has identified at least 50 olfactory genes which are switched on in some people and not in others. They believe this may explain why some of us love some smells and tastes while others hate them. The Israel researchers say their study shows that nearly every human being shows a different pattern of active and inactive smell-detecting receptors.
1. What did Richard Axel and Linda Buck find out?| A．The category of food smells. |
| B．The logical part of human brain. |
| C．The nature of human olfactory system. |
| D．The relationship between food and feelings. |
| A．Bread. | B．Fruits. |
| C．Coffee. | D．Fast food. |
| A．Some people can recognize up to 50 smells. |
| B．Every person has a different pattern of genes. |
| C．Different people are sensitive to different smells. |
| D．There are still some olfactory genes to be found out. |
| A．Logic and behaviour. |
| B．Smell and its influence. |
| C．Sense ability and food tastes. |
| D．Olfactory genes and its system. |
7 . A year ago， Jiao Wenchao， 31 and a college teacher， suddenly realized that he was having hearing problems． The problem grew to such a degree that he decided to seek professional help at a local hospital in Beijing． An examination suggested that both his ears were losing the ability to hear high frequency sounds．
The doctor told him that the problem was caused by over exposure to high frequency and loud noise， including from his earphones．
Neurological hearing loss， as in Jiao's case， is usually caused by exposure to unsafe noise levels， says Pan Tao， an otologist from the Peking University Third Hospital in Beijing． His department receives around 10 patients who have neurological hearing impairment like Jiao every day．
"Such patients are increasing in recent years． Even some teenagers are among them，" says Pan． "And during our investigations， we find that many of them follow bad habits such as making phone calls or listening to music for too long and at high volume．"
A recent report by the World Health Organization has warned that some 1.1 billion teenagers and young adults are at risk of hearing loss due to the unsafe use of personal audio devices， including smart phones． Data from studies in middle-and high-income countries analyzed by WHO indicate that among teenagers and young adults aged between 12 and 35， nearly 50 percent were exposed to unsafe levels of sound from personal audio devices and around 40 percent were exposed to potentially damaging levels of sound at entertainment venues．
According to the study， safe listening depends on the intensity or loudness of sound， as well as the duration and frequency of listening． When the exposure is particularly loud， regular or prolonged， it could lead to permanent damage of the ear's sensory cells， it says．
The study results have grabbed wide attention on the internet in China． Many internet users admit that compared with more noticeable health problems like eyesight loss， hearing loss has been largely neglected． Pan says such impairment is usually neglected even by patients themselves as it is usually in the high frequency section， which means that those who suffer it can still carry out daily communication unaffected．
"Often the problem is only found out when they visit our hospital to seek help for more noticeable symptoms like tinnitus，" says Pan． He also says that timely treatment is critical． "This is because sometimes the hearing loss is temporary and can be cured with therapy， including medicine． However， it can become irreversible if the problem is not properly treated within the first two or three months．
"But many people miss the best time to get treated because they do not even realize the existence of the problem．"
After Jiao's first check a year ago， the doctor prescribed Jiao medicine to tackle the problem． However， Jiao returned to the hospital recently， and found that the situation had not improved much． "I understand now that the impairment may be irreversible，" says Jiao． "So， I must pay attention to my habit of using earphones， and avoid harmful environmental noises， too．"
To mark International Ear Care Day， celebrated each year on March 3， WHO has launched the "Make Listening Safe" initiative to draw attention to the dangers of unsafe listening and promote safer practices．
The WHO study has suggested that unsafe levels of sounds could be exposure to in excess of 85 decibels for eight hours or 100 dB for 15 minutes， such as noise at nightclubs， bars， sporting events and other entertainment venues．
The study also warns that hearing loss has potentially devastating consequences for physical and mental health， education and employment． It says teenagers and young people can better protect their hearing by keeping the volume down on personal audio devices， wearing earplugs when visiting noisy venues， and using carefully fitted， and， if possible， noise-canceling earphones or headphones．
1. According to the study， safe listening depends on ______ ．| A．The intensity of sound． |
| B．The loudness of sound． |
| C．The duration and frequency of listening． |
| D．All of the above． |
| A．Congenital diseases． |
| B．Overuse of earphones． |
| C．Over exposure to loud noise． |
| D．Over exposure to high frequency noise． |
| A．Patients， like Jiao Wenchao， are merely limited to adults． |
| B．Sometimes the hearing loss is temporary and can be cured with therapy． |
| C．In Jiao Wenchao's case， timely treatment is critical． |
| D．WHO has launched some initiatives to draw attention to the dangers of unsafe listening． |
| A．It is harmful to stay in bars for hearing for a while． |
| B．Environmental noises have no effects on people． |
| C．People working at nightclubs are apt to lose hearing ability． |
| D．Patients suffering from listening loss would immediately realize the importance of treatment． |
8 . Unless you’re very young or very old,it's likely you have some kind of relationship with email, whether you get hundreds of messages a day or a few dozen a week. A new study suggests that how we deal with these incoming messages could be affecting our stress levels and overall health.
A team from the Future Work Centre in the UK surveyed 2,000 people across various industries, sectors, and job roles, asking participants how they managed their email and how much associated stress they felt as a result. Overall, those who spent the most time organising and staying on top of messages felt the most email-related pressure too.
“While email can be a valuable communication tool, it’s clear that it’s a source of stress of frustration for many of us. The people who reported it being most useful to them also reported the highest levels of email pressure!” said one of the team, Richard MacKinnon.
Two of the habits linked to more email-related stress were checking for messages first thing in the morning and last thing at night. Half of those surveyed had push notifications (消 息推送）set up for new email, while 62 percent of respondents left their email app open all day and all night. Both were linked to higher levels of email pressure. The survey also found that managers suffered more than non-managers.
Stress is not just a problem when it comes to our mood—it’s been linked to a lot of disorders such as heart disease， weight gain， memory impairment (减弱），digestive problems,and depression.
The researchers suggest that the relationship between email-related stress and the negative impact on home life is not the same for everyone.
1. What’s the purpose of the study?| A．To find out how many people have an email account. |
| B．To know what sort of people use email most. |
| C．To find out how email management is related to stress. |
| D．To show what changes email has brought about to people. |
| A．It brings more strengths. | B．It is not an essential tool. |
| C．It is a double-edged sword. | D．It makes people puzzled. |
| A．Checking email in the morning. |
| B．Checking email in the evening. |
| C．Keeping email app open at work. |
| D．Setting up push notifications for new email. |
| A．Science fiction. | B．A science report. |
| C．fashion magazine. | D．A book guide. |
9 . Eye Health Care Daily
Healthy habits mean healthy eyes. Here are some daily tips for eye health.
◆Clean your eyes with pure cold water regularly. This is one of the best ways to keep eyes healthy and disease free.
◆Avoid looking directly at the sun.
◆Roll your eyes up and down, then side to side. Then move your eyes in a circular motion (圆周运动). Exercise 5 to 10 times a day to relax your eyes.
◆ Keep a good distance from the computer screen-sit about 22-28 inches away from it.
◆Visit your eye doctor on a regular basis.
There are also some tips for healthy contact lens (隐形眼镜) wear and care to help prevent eye infections (感染). Please visit CDCS healthy contact lenses website and you can also follow them on social media (www.cdc.goy/contactlenses).
1. _____is not good for your eyes.| A．Eating vegetables | B．Wearing sunglasses |
| C．Wearing contact lens | D．Looking at the sun directly |
| A．Clean eyes with pure cold water. | B．Look at the sun directly. |
| C．Make eye movements. | D．Wear contact lens. |
| A．Education. | B．Health. |
| C．Entertainment. | D．Advertisement. |
10 . Protecting your eyesight is one of the most important things you can do to help maintain your quality of life.
Protect your eyes from harmful UV(紫外线的) light. When you stay outdoors during daytime, always wear sunglasses that protect your eyes from 100 percent of the sun’s harmful UV rays.
Look for warning signs of changes in your vision.
| A．This may help reduce your risk of cataracts(白内障) and other problems. |
| B．Test your eyesight for free in an online eye exam. |
| C．In a word, eye care is very important, no matter how old a person is. |
| D．With a little careful and loving care, you can keep your eyes healthy as you age. |
| E．Get your eyes checked at least every two years. |
| F．It’s true that following these steps is no guarantee of perfect vision through your lifetime. |
| G．If you start noticing changes in your vision, see your eye doctor immediately. |
