We have all experienced that feeling of mental exhaustion after focusing on a tricky problem. Detailed thinking certainly feels like hard work, but is it? The answer is a touch more subtle than you might suspect. Intriguingly, when it comes to energy use, the brain doesn’t distinguish between tasks that we traditionally regard as “hard” and those that come more naturally. This was first demonstrated in the 1950s in a study showing that the brain’s level of metabolism (新陈代谢) is remarkably constant, regardless of whether we are concentrating on mental math or letting our mind wander.
Your brain assigns resources to its different parts depending on the mental activity being carried out. But there is a trade-off. “When the demand of a mentally challenging task increases, you see increased metabolism in the neurons (神经元) responsible for the task,” says Nilli Lavie at University College London. Meanwhile, you see corresponding decreases in other brain areas. For instance, Lavie and her colleagues measured energy use in the brain region responsible for daydreaming and found that it decreased when volunteers carried out a problem-solving task that required focused attention. So thinking hard does burn more energy in the brain region involved, but this is offset by energy savings in other parts of the brain.
However, your brain doesn’t see it that way. “It worries about an imbalance of supply over demand,” she says. When the brain detects exhaustion of glucose (葡萄糖) — the sugar that fuels the brain — in any region, it perceives it as something bad. This is what gives rise to the feeling of being worn out after continuous focus.
So, after a tough exam, the sensation of having burned through a supercomputer’s worth of energy is real, though your brain has used few or no extra calories overall. “There is a constant rate of neural energy in the brain,” says Lavie. “It is irrelevant whether it is spent on a task requiring concentration or on a distraction.”
1. What is the main idea of paragraph 1?| A．We all get tired after hard focus. |
| B．Thinking hard doesn’t use more energy. |
| C．A study shows the brain’s metabolism level. |
| D．Detailed thinking is considered harder than mind wandering. |
| A．It burns an increased rate of calory. |
| B．It stimulates the neurons for the task. |
| C．It’s also involved in the task and requires energy. |
| D．It reduces neural activity and spares more energy. |
| A．Balanced. | B．Absorbed. | C．Dominated. | D．Released. |
| A．The brain detects signals of high energy demand. |
| B．The brain is punishing you for working too hard. |
| C．The brain is losing the balance of energy supplying. |
| D．The brain gets bored easily and refuses to be engaged. |
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【推荐1】So many things can keep you from seeing your loved ones in person. Fortunately, thanks to modern technology, the people we miss are often only a phone call or text message away. But according to science, if you want to feel more connected to the people you’re talking to, you should call them instead of texting.
A new study, published in the Journal of Experimental Psychology, found that communication interactions that included voice created stronger social relationships than communication through typing.
In the study, researchers conducted various experiments. In the first one, they asked 200 people to make predictions about what it’d be like to reconnect with an old friend by email or by phone and then assigned people at random to do one or the other. Although people expected that a phone call would be more awkward, hearing someone’s voice actually made the experience better.
“People reported they did form a significantly stronger bond with their old friend on the phone compared with email, and they didn’t feel more awkward,” said study co-author Amit Kumar.
In another experiment, the researchers had strangers connect by either texting, talking over video chat, or talking using only audio. They found that both forms of voice communication made the strangers feel much more connected than when they communicated via text.
Sabrina Romanoff, a Harvard psychologist, says people tend to text or email instead of calling because of convenience as they see it as a controlled form of communication where they can “respond to information exactly in the way they intend without unexpected additions by the other person”. However, in fact, texting can make it hard to determine the true meaning behind a conversation. “A phone call is actually more convenient when considering the real effects of the message,” she explains. “Each party is more present, and therefore, able to understand the meaning behind the content without thinking over the endless possible meanings behind words.”
1. Which is the best for building closer connections according to the new study?| A．An email. | B．A video chat. |
| C．A text message. | D．A letter. |
| A．They made predictions on the others’ intentions. |
| B．They made random phone calls to some strangers. |
| C．They imagined the joy of hearing someone’s voice. |
| D．They predicted a phone call would be embarrassing. |
| A．It can improve your communication skills. |
| B．It proves a controlled form of communication. |
| C．It can make it easier to understand each other. |
| D．It avoids unexpected additions in conversations. |
| A．You Should Call Instead of Texting | B．Technology Builds More Connections |
| C．Communicate With Your Old Friends | D．Voice Communication Is Time-saving |
【推荐2】Music is known to have a great deal of mental and physical benefits on humans. From helping to treat physical medical problems to relieving stress, music can be extremely beneficial in helping to improve health.
Animals may have a great deal of stress.
Music can be extremely beneficial for animals in high stress situations.
| A．It can create a space for them. |
| B．The same goes for our furry friends, too. |
| C．They could be stressed for a variety of reasons. |
| D．It would be a beneficial practice for all parties. |
| E．Another place where music can be helpful is in car rides. |
| F．There are ways that you can identify stress in your animals. |
| G．It’s no wonder loud noises can cause dogs and cats so much stress. |
【推荐3】Many animals climb, but few do it as well as the spiders. These eight-legged creatures can be anywhere. Now researchers have come up with surprising clues as to how spiders can stick to almost any surface. The structure of tiny hairs at the tips of the spiders’ legs likely help them hang on.
Clemens Schaber, who led the new study, said, “Adhesion, or stickiness, is an important part of that. Spiders don’t have a sticky liquid on their feet. Instead, they use ‘dry’ adhesion. Animals that use dry adhesion can stick and unstick to surfaces easily.”
At the end of a spider’s leg, there are some so-called hairs. At the tips of these hairs are small, flat structures that look like spatulas. When the hairs touch something, these “spatulas” form bonds with the surface and stick. Before this latest research, Schaber knew the hairs were important for adhesion. He wanted to know more about why they worked so well.
They first tried to pull the hairs off the spider legs. But the whole leg often came off. This is a natural defense that the spiders use to escape their enemies. Then they used a powerful microscope to view the hairs up-close. Schaber expected that all the hairs would point in the same direction, more or less. But it wasn’t like that. Instead, as the researchers looked at the tip up-close, they saw the ends of the hairs were all a little bit different in direction.
The researchers then tested the stickiness of the hairs on different materials. They found that some hairs had the strongest adhesion at one angle. Others worked best at other angles. So this mix of angles and adhesions may help the spider stick no matter how it touches a wall.
“The study is quite interesting,” said Schaber. “It shows us new ways to think about making structures stick to surfaces.”
1. What did the researchers find in the study?| A．Spiders’ motivation to climb. | B．Spiders’ sticky liquid on their feet. |
| C．The secret to spiders’ ability to stick. | D．The existence of hairs on a spider’ s legs. |
| A．The real purpose of the study. | B．The shapes of so-called hairs. |
| C．The stickiness level of so-called hairs. | D．The link between surface and stickiness. |
| A．The shape of spatulas. | B．The number of tiny hairs. |
| C．The direction of tiny hairs. | D．The importance of tiny hairs. |
| A．It shows us new ways to study animals. | B．It gives humans more creative ideas. |
| C．It proves humans can climb as spiders. | D．It helps to find a naturally sticky material. |
【推荐1】If you think that running marathons (马拉松) will help you live a long and healthy life, new research may come as a shock. According to a recent scientific study, people who do a very strenuous workout are as likely to die as people who do no exercise at all.
Scientists in Denmark have been studying over 1,000 joggers (慢跑者) and non-joggers for 12 years. The death rates from the sample group indicate that people who jog at a moderate (适度的) pace two or three times a week for less than two and a half hours in total are least likely to die. The best speed to jog at was found to be about 5 miles per hour. The research suggests that people who jog more than three times a week or at higher speeds of over 7 mph die at the same rate as non-joggers. The scientists think that this is because strenuous exercise causes structural changes to the heart and arteries (动脉). Over time, this can cause serious injuries.
Peter Schnohr, a researcher in Copenhagen, said,” If your goal is to decrease risk of death and improve life expectancy, jogging a few times a week at a moderate pace is a good polity. Anything more is not just unnecessary, and it may be harmful.”
The implications (暗示) of this are that moderate forms of exercise such as tai chi, yoga and brisk walking may be better for us than “iron man” events, triathlons and long-distance running and cycling. According to Jacob Louis Marott, another researcher involved in the study, “You don’t actually have to do that much to have a good impact on your health. And perhaps you shouldn’t actually do too much”.
1. The underlined word “strenuous” in Paragraph 1 is closest in meaning to “______________”.| A．hard | B．regular |
| C．practical | D．enjoyable |
| A．suggest giving up jogging | B．show risks of doing sports |
| C．provide supportive evidence | D．introduce the research process |
| A．It may injure the heart and arteries | B．It can exhaust the body and soul |
| C．It will bring too much pressure | D．It might cause worse exercise performance |
| A．No exercise at all is the best choice. | B．More exercise means a healthier life. |
| C．Marathon runners are least likely to die. | D．Proper exercise results in good health. |
After World War II，the population of most large American cities decreased；however, the population in many Sun Belt cities increased．In the late 1940s and early 1950s，city residents became wealthier．They had more children so they needed more space．They moved out of their apartments in the city to buy their own homes．They bought houses in the suburbs（郊区）．
Now things are changing，the children of the people who left the cities in the 1950s are now adults．Many, unlike their parents，want to live in the cities．They continue to move to Sun Belt cities and older ones of the Northeast and Midwest．Many young professionals are moving back into the city．They prefer the city to the suburbs because their jobs are there；or they just enjoy the excitement and possibilities that the city offers．
This population shift（迁移）is bringing problems as well as benefits．Countless poor people must leave their apartments in the city because the owners want to sell the buildings or make apartments for sale instead of for rent．In the 1950s，many poor people did not have enough money to move to the suburbs；now many of these same people do not have enough money to stay in the cities．
Only a few years ago，people thought that the older American cities were dying．Some city residents now see a bright，new future．Others see only problems and conflicts．One thing is sure：many dying cities in America are alive again．
1. What does the author think of cities all over the world?
| A．They are dying． | B．They are hopeless． |
| C．They are similar． | D．They are different． |
| A．Because older American cities were dying． |
| B．Because they were richer and needed more space． |
| C．Because cities contained the worst parts of society． |
| D．Because they could hardly afford to live in the city． |
| A．are faced with housing problems |
| B．are forced to move back to the suburbs |
| C．want to sell their buildings |
| D．need more money for daily expenses |
| A．American cities are changing for the worse |
| B．people have different views on American cities |
| C．older people prefer the city to the suburbs in America |
| D．the population is decreasing in older American cities |
【推荐3】Technology has been around for a long time, and we’ve used it as a tool to communicate more rapidly and effectively. But in the past few years, technology has almost taken the place of conversation. People send messages back and forth, not realizing that they never have live contact with the other person. “That’s OK, right?” one might ask. “We’re still communicating. The relationship looks a little different, but we’re still connecting back and forth.” One study showed that only 7 percent of communication is the words we use. Thirty-eight percent is our tone of voice, and 55 percent is body language. In face-to-face conversation, we’re using all three. On the phone, we’ve lost the body language—so we’re down to two. When our communication is completely through email, texting or social media, we’re down to one.
Some people deem that technology is the enemy because it’s robbing people of their conversational skills. Indeed, sharing words in print is a form of communication, but it doesn’t convey the emotion that comes through tone of voice, facial expression, and body language. Written words can’t hold or hug. Written words can’t listen or make eye contact. When I wrote You Can? Text a Tough Conversation, I interviewed a lot of people. Most of them loved their technology. But most of them also felt like it had got out of control, and it was messing up their relationships in some way.
Technology isn’t the enemy; it’s just a tool. It’s like a small sharp knife used by a doctor for doing an operation. In the hands of a skilled surgeon, it’s good. In the hands of a crazed criminal, it’s bad. Technology isn’t going anywhere either. The key is figuring out how to get them to work together. It’s like two porcupines(豪猪)that fall in love. They need each other, but have to learn how to keep from sticking each other and causing pain.
1. What will happen if our communication is completely through texting?| A．We’ll lose 55 percent of the tools that help us connect. |
| B．We’ll lose 45 percent of the tools that help us connect. |
| C．We’ll lose 62 percent of the tools that help us connect. |
| D．We’ll lose 93 percent of the tools that help us connect. |
| A．Explore. | B．Record. | C．Doubt. | D．Consider. |
| A．It becomes popular. | B．It lacks human touch. |
| C．It destroys many relationships. | D．It makes life much easier. |
| A．It cannot go too far in relationships between people. |
| B．It cannot take the place of traditional conversation. |
| C．Whether it’s positive or negative depends on how we use it. |
| D．It should be used more smartly in the fields of medical care. |
