When we give blood or need a blood transfusion, we have to think about our blood types — or blood groups as scientists refer to them.
But how much do animals think about their blood types? Probably never, given what we know about animals. But we humans do think about our animals, because sometimes animals receive blood transfusions too, and we want to make sure the blood we’re giving doesn’t cause a blood incompatibility reaction. That’s a negative reaction, causing the recipient’s immune system to attack foreign blood, producing antibodies (抗体) against the red blood cell proteins, or antigens (抗原), in the donated blood. Although all animals have blood groups, every species has a different system, and we know the most about the systems of domesticated mammals.
Dogs, for their part, have more than 8 different antigens that can attach to their red blood cells. Most of them are labeled Dog Erythrocyte Antigen (DEA 1.1, 1.2, 3, 4, 5, 6 and 7). Often, individuals within a specific breed of dogs will have the same blood type — for instance,60 percent of greyhounds fall into the DEA 1.1 negative (the universal dog donor) blood group. But new dog blood groups are still being detected — the recently discovered Dal blood group, for example, is only found in Dalmatians.
Cats, on the other hand, have only 2 possible antigens — A and B, although they aren’t the same A and B antigens found in human blood. There is no universal donor or recipient feline blood groups, but the vast majority (around 90 percent) of domestic cats have type A blood, while more special purebreds often type B. AB is also possible, but very rare.
Like dogs, horses’ blood groups are loosely organized along breed lines, but there are 30 different groups. That represents combinations of 8 different antigens (A, C, D, K, P, Q and U are internationally recognized, while T is still being researched). Cows are tricky because there are 11 major blood groups (A, B, C, F, J, L, M, R, S, T and Z), but the B group includes over 60 different antigens, making blood matches for transfusions tough.
1. Why can’t an unmatched blood transfusion be given?| A．It causes a positive reaction. | B．It produces antibodies in the blood. |
| C．It causes genes to change. | D．It produces the red cell proteins. |
| A．Dogs have the same blood types as horses. |
| B．Dal blood group is very common. |
| C．The DEA 1.1 negative blood group is common. |
| D．The blood types of dogs are very rare. |
| A．Scientific. | B．Opposed. |
| C．Changeable. | D．Negative. |
| A．A Research on Animal’s Blood Types. | B．Animal’s Safe Blood Transfusion. |
| C．Animal’s Blood Types and Transfusion. | D．Domesticated Mammals. |
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【推荐1】When using the Internet to fill-in gaps in one’s own knowledge — people believe they’re smarter and have a better memory than others, and incorrectly predict that they’ll perform better on future knowledge tests they take without Internet access, according to the new research.
“When we’re constantly connected to knowledge, we mistake the Internet’s knowledge for our own,” says Adrian Ward of the University of Texas. “Besides, the Google search process is also much like searching your own memory, which might cause people to confuse information found online with information in their own heads.”
To investigate that, Ward, in the first experiment, got participants to answer ten general knowledge questions either on their own or using online search. Then, they reported how confident they were in the ability to find information by using external sources, and in their own ability to remember information. Participants who used Google answered more questions correctly and were also more confident in their own memory.
In a second experiment, participants were made to answer the same ten general knowledge questions either on their own or using the online searching engine. Then, Ward told them they’d take second knowledge test without using any outside sources. Those who completed the first knowledge test with Google thought they’d know significantly more when forced to rely on their own memory in the future — suggesting they attributed their initial performance to their own knowledge, not to the fact they were using Google.
In a final experiment, participants were made to answer knowledge questions on their own, using Google, or with a version of Google that delayed search results by 25 seconds. Unlike those who used standard Google, participants who used “slow Google” weren’t more confident in their internal knowledge and didn’t predict higher performance on future tests. This suggests that in a world in which searching online is often faster than using our memory, we may know less but think we know more.
Ward says that the research has major implications for education, as students might devote less time and energy to gaining knowledge if they already feel knowledgeable. “Maybe we can use our limited cognitive resources in a more effective and efficient way,” Ward says.
1. How does Adrian Ward draw his conclusions?| A．By carrying out a series of experiments. | B．By referring to previous related research. |
| C．By comparing ways of using the Internet. | D．By analyzing the effects of Internet access. |
| A．Compared. | B．Owed. | C．Referred. | D．Devoted. |
| A．It can improve one’s mental development. | B．It can affect the way we think about ourselves. |
| C．It can make one become smarter academically. | D．It can change our view of our own intelligence. |
| A．Show more experiments. | B．Give some suggestions. |
| C．Provide a certain theory. | D．Analyze a real-life phenomenon. |
【推荐2】Have you ever wondered why hair turns gray as you get older and whether there is something you can do to prevent graying or at least slow it down? Here's a look at what causes hair to turn gray and some of the factors that affect graying.
The age at which you'll get your first gray hair （supposing your hair doesn't simply fall out） is largely decided by genetics. You'll probably get that first strand （缕）of gray hair around the same age your parents and grandparents started to go gray. However, the rate at which the graying progresses is somewhat under your own control. Smoking is known to increase the rate of graying. Generally poor nutrition, insufficient B vitamins, anemia, and untreated thyroid （甲状腺）conditions can also speed the rate of graying.
What causes your hair's color to change? That has to do with the process controlling the production of the paint called melanin （黑色素），the same material that tans your skin in response to sunlight. Every hair cell contains melanin cells called melanocytes. The melanocytes produce eumelanin（真黑素），which is black or dark brown, and pheomelanin, which is reddish-yellow, and pass the melanin to the cells which produce keratin （角蛋白）, the chief protein in hair. When the keratin-producing cells die, they keep the coloring from the melanin. When you first start to go gray, the melanocytes are still present, but they become less active. Less paint is kept into the hair so it appears lighter.
As graying progresses, the melanocytes die off until there aren't any cells left to produce the color. While this is a normal and unavoidable part of the aging process and is not of itself associated with disease, some autoimmune diseases can cause premature graying. However, some people start going gray in their 20s and are perfectly healthy.
Extreme shock or stress can also cause your hair to go gray very quickly, though not overnight.
1. What determines your first strand of gray hair?| A．Genes. | B．Ages. | C．Nutrition. | D．Disease. |
| A．Avoids. | B．Protects. |
| C．Sunburns. | D．Covers. |
| A．It helps the hair keep shining. | B．It can prevent the hair turning gray. |
| C．It is mainly made of hair protein. | D．It makes the hair look lighter. |
| A．The process of hair changes. |
| B．The causes of hair turning gray. |
| C．The factors of hair components. |
| D．Relationship between gray hair and health. |
【推荐3】When we hold our breath and go underwater, we’ll soon be unable to stand it.
Sama-Bajau is a collective term (集合术语) that refers to several closely related native peoples. The Bajau live on long houseboats or small wooden houses that are built on the sea, close to the shore in Southeast Asia.
As they make their living primarily from fishing, they have become expert free divers (自由潜水者). Bajau divers have the longest daily diving time without breathing among allhumans.
It appears that centuries of free diving have scientifically distinguished the Sama-Bajau. According to research, the Bajau’s spleens (脾脏) are much larger than the average people’s on land.
| A．Larger spleens can have some weaknesses. |
| B．Therefore, many older divers are hard of hearing. |
| C．The difference makes the Bajau quite able to dive underwater. |
| D．They only go ashore to trade or seek shelter during sea storms. |
| E．Bajau children master swimming and diving skills at an early age. |
| F．The existence of this special group of people is threatened nowadays. |
| G．With free diving training, we can increase the time underwater by a few minutes. |
【推荐1】Learning a second language is tough at any age. Now, in a new study, scientist have found out the exact age after which your chances of reaching fluency（流利）in a second language seem to plummet:10.
The study published in the journal Cognition, found that it's "nearly impossible" for language learners to reach native-level（母语水平）fluency if they start learning a second language after age 10. "It turns out you're still learning fast," says study co-author Joshua Hartshorne. "It's just that you run out of time, because your ability to learn starts dropping at around 17 or 18 years old," People who start a few years after age 10 may still become quite good at a language, the authors say, but they are unlikely to become fluent.
Kids may be better than adults at learning new languages for many reasons. Children's brains are more plastic than those of adults, meaning they're better able to adapt and respond to new information. Kids may also be more willing to try new things than adults are. Their comparatively new understanding of their native language may also be advantageous.
These findings may seem discouraging, but it was inspiring for scientists to learn that the key period for fluent language learning might be longer than previously thought. Some scientists believed that the window begins to close shortly after birth, while others made it longer to very early childhood. Compared with those judgments-age 17 or 18 —when language learning ability start to drop off—seems relatively old.
For this study, the researchers created an online test promising to guess people's native language and home country based on their responses to English grammar questions. Almost 670,000 people took it, giving the researchers huge amounts of data from English speakers of many ages and backgrounds. Examining the responses and grammar mistakes allowed them to made unusually exact judgments about language learning.
1. What does the underlined word "plummet" in paragraph 1 mean?| A．Drop sharply. | B．Increase greatly. |
| C．Appear gradually. | D．Double suddenly. |
| A．Adults tend to perform badly in learning a second language. |
| B．Children are at an advantage in acquiring a new language. |
| C．All these new findings are quite discouraging for scientists. |
| D．People have different key periods for mastering a language. |
| A．The purpose of the study. | B．The findings of the study. |
| C．The subject of the study. | D．The process of the study. |
| A．Kids Are Better at Learning New Languages |
| B．Adults Can't Learn a Second Language Well |
| C．Never Say Die When Learning a New Language |
| D．Better to Learn a New Language Before Age 10 |
【推荐2】There are positive effects of having deep conversations with strangers.
“Connecting with others in meaningful ways tends to make people happier, and yet people also seem unwilling to engage in deeper conversations, said Nicholas Epley, a professor of behavioral science at the University of Chicago. “This struck us as an interesting social paradox: If connecting with others in deep and meaningful ways increases well-being, then why aren’t people doing it more often in daily life?”
To answer that question, Epley and his colleagues designed several experiments, where pairs of people-mainly strangers-were asked to discuss either relatively deep or shallow topics. Before the conversations, participants predicted how awkward they thought the conversations would be, how connected they thought they would feel to their conversation partner and how much they would enjoy the conversation. Afterward, they rated their predictions on actual basis. Generally, the researchers found that deep conversations felt less awkward and led to greater feelings of connectedness and enjoyment than the participants had expected.
If deep connection is better, then why aren’t people actually having more of them? The researchers suspected it might be because people underestimate how interested strangers are in learning about their deeper thoughts and feelings. In some of the experiments, the researchers asked participants to predict how interested their conversation partner would be in the discussion, and then afterward to indicate how interested their partner actually was in the discussion. On average, people consistently underestimated how interested their partners would be in learning about them.
“People seemed to imagine that revealing something meaningful about themselves in conversation would be met with blank stares and silence, only to find this wasn’t true in the actual conversation,” Epley said. “Human beings are deeply social and tend to reciprocate in conversation. If you share something important, you are likely to get something important exchanged in return, leading to a considerably better conversation.”
These findings are published in the Journal of Personality and Social Psychology.
1. What do we know from Paragraph 3?| A．The experiments were carried out on a regular basis. |
| B．Most of the participants are familiar with each other. |
| C．The participants gave evaluations on their predictions. |
| D．The topics discussed focused on meaningful contents. |
| A．Depth of the topic. | B．People’s assumption. |
| C．Participants’ interest. | D．Consistency of the talk. |
| A．Respond. | B．Withdraw. | C．Postpone. | D．Explain. |
| A．To provide suggestions. |
| B．To promote communication skills. |
| C．To explain a phenomenon. |
| D．To introduce a scientific study. |
【推荐3】Japan has announced emergency Covid measures in Tokyo and three other areas in order to control rising infections (传染病), just three months before the country is set to host the Olympics. The government said the state of emergency — set to last for about two weeks — would be “short and powerful”. Under the measures, bars will be required to close and big sporting events will be held without audience. The government has insisted that the Olympics will go ahead in July.
Prime minister Yoshihide Suga announced the measures on Friday, saying they would begin on Sunday and remain in place until 11 May. In addition to to Tokyo, Osaka, Kyoto and Hyogo will be affected. It has marked the third state of emergency in japan since the pandemic began. “I sincerely apologize for causing trouble for many people again,” he said. “It is feared that infection in major cities will spread across the whole country if we take no measures.”
Under the rules, major facilities like department stores will close, as well as restaurants, bars, and KTV rooms serving alcohol. Restaurants that do not serve alcohol are being told to close early, and companies are being asked to make arrangements for people to work remotely. Schools will remain open. Besides, the emergency measures coincide with the country’s “Golden Week” holiday, which runs from late April to the first week of May and is the busiest travel period of the year. Tokyo governor Yuriko Koike urged residents to start taking precautions immediately. In an effort to discourage people from going out at night. She said neon signs (霓虹灯) would be turned off.
The coronavirus toll in Japan has been much lower than that in many other countries, with about 558,000 cases and fewer than 10,000 deaths, according to figures collected by Johns Hopkins University. But there are concerns over the latest rise in infections, with reports of hospital bed shortages in some areas.
Tokyo 2020 president Seiko Hashimoto said at a news conference on Friday that organizers were not considering canceling the event. “I hope the coronavirus situation improves with the prevention measures the government, Tokyo, and other regional governments have put into place,” she said. “We, as Tokyo 2020, continue to wish for the swift return to normal and will continue to work closely to make sure a safe and secure Olympics can happen.”
1. According to the passage, what does Japanese government advise people to do?| A．To watch a live game. | B．To work at home. |
| C．To hang out in the evening. | D．To study at home. |
| A．To relieve people's fear of the the pandemic. |
| B．To settle the problem of hospital bed shortages. |
| C．To test government’s management of emergency. |
| D．To ensure the smooth running of the upcoming Olympics. |
| A．generous and brilliant. | B．costly but useless. |
| C．positive and considerate. | D．accidental but efficient. |
| A．meet with | B．deal with | C．make up | D．set up |
