With around 100 students scheduled to be in that 9 am Monday morning lecture, it is no surprise that almost 20 people actually make it to the class and only 10 of them are still awake after the first 15 minutes; it is not even a surprise that most of them are still in their pyjamas (睡衣). Obviously, students are terrible at adjusting their sleep cycles to their daily schedule.
All human beings possess a body clock. Along with other alerting (警报) systems, this governs the sleep/wake cycle and is therefore one of the main processes which govern sleep behaviour. Typically, the preferred sleep/wake cycle is delayed in adolescents, which leads to many students not feeling sleepy until much later in the evenings. This typical sleep pattern is usually referred to as the “night owl” schedule of sleep.
This is opposed to the “early bird” schedule, and is a kind of disorder where the individual tends to stay up much past midnight. Such a person has great difficulty in waking up in the mornings. Research suggests that night owls feel most alert and function best in the evenings and at night. Research findings have shown that about 20 percent of people can be classified as “night owls” and only 10 percent can be classified as “early birds”—the other 70 percent are in the middle. Although this is clearly not true for all students, for the ones who are true night owls this gives them an excellent excuse for missing their lectures which unfortunately fall before midday.
1. What does the author stress in Paragraph 1?| A．Many students are absent from class. |
| B．Students are very tired on Monday mornings. |
| C．Students do not adjust their sleep patterns well. |
| D．Students are not well prepared for class on Mondays. |
| A．Most students prefer to get up late in the morning. |
| B．Students don’t sleep well because of alerting systems. |
| C．One’s body clock governs the sleep/wake cycle independently. |
| D．Adolescents’ delayed sleep/wake cycle isn’t the preferred pattern. |
| A．Functions of the body clock. | B．The “night owl” phenomenon. |
| C．Human beings’ sleep behaviour. | D．The school schedule of “early birds”. |
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【推荐1】If you’ve spent any amount of time boating, fishing, or bird-watching at lakes and rivers, you have most likely seen fishes jumping out of the water. I have seen it many times. Certainly, fishes will exit water in desperate attempts to escape enemies. Dolphins take advantage of the behavior, forming a circle and catching the frightened fishes in midair. But just as we may run fast from fun or from fear, different emotions might motivate fishes to jump.
Mobula rays (蝠鲼) aren’t motivated by fear when they throw their impressive bodies — up to a seventeen-foot wingspan (the distance from the end of one wing to the end of the other) and a ton in weight — skyward in leap of up to ten feet. They do it in schools of hundreds. They usually land on their bellies, but sometimes they land on their backs. Some scientists think it might be a way of removing parasites (寄生虫). But I think that the rays are enjoying themselves.
In the clear waters of Florida’s Chassahowitzka National Wildlife Refuge, I watched several schools of fifty or more mullets(鲻鱼) moving in beautiful formation. Their well-built bodies were most evident when they leaped from the water. Most of the time I saw one or two leaps by a fish, but one made a series of seven. They usually land on their sides. Each jump was about a foot clear of the water and two to three feet in length.
Nobody knows for sure why the fish leaps. One idea is that they do it to take in oxygen. The idea is supported by the fact that mullets leap more when the water is lower in oxygen, but is challenged by the likelihood that jumping costs more energy than is gained by breathing air. It is hard to imagine they will feel any fresher when back in water.
Might these fishes also be leaping for fun? There is some new evidence. Gordon M. Burghardt recently published accounts of a dozen types of fishes leaping repeatedly, sometimes over floating objects — sticks, plants, sunning turtle — for no clear reason other than entertainment.
1. What can we say about the dolphins in Paragraph 1?| A．They have great escaping skills. | B．They are easily frightened. |
| C．They are very clever. | D．They love jumping. |
| A．Both do it in groups. | B．Both land on their bellies. |
| C．Both jump many feet out of water. | D．Both make leaps one after the other. |
| A．Anxious. | B．Indifferent. |
| C．Approving. | D．Questionable. |
| A．To remove parasites. | B．To amuse themselves. |
| C．To take in more oxygen. | D．To escape enemies. |
【推荐2】Last month, a study was published that examined climate change’s direct effects on the Earth’s seasons. Scientists found a connection between climate change and the temperature and duration of the summer season. Summers in the Northern hemisphere(北半球) could last nearly six months by the year 2100 if global warming continues, according to the study. With the seasons off-balance, there will be harmful effects on human health and agriculture.
Yuping Guan, a physical oceanographer at the State Key Laboratory of Tropical Oceanography at the Chinese Academy of Sciences, and his colleagues combined daily climate data from 1952 to 2011 to get a sense of the start and end of each season in the Northern hemisphere. Over the nearly 60-year period, they discovered that, on average, summers grew from 78 to 95 days, while winters shortened from 76 to 73 days. The spring and autumn seasons also shortened. Guan and his team used the findings from the data to create a model to hypothesize (假设) about how the seasons would possibly change in the future. They found that if left untouched, summers in the Northern hemisphere could last nearly six months, while winters could contract to less than two months.
If the Earth’s seasons continue to shift, it will bring negative effects to human health and agriculture. Longer and hotter summers, for example, can cause mosquitoes and other disease-carrying insects to potentially expand their scope and land in places where they’re usually not found. “Because seasons influence the life cycles of plants and animals, climate change could disturb species’ ability to adapt,” said Scott Sheridan, a climate scientist. “If seasons continue to change, everything isn’t going to change perfectly as they should. If we take the example of flowers coming out of the ground, those flowers could come out, but bees aren’t there to pollinate them yet or they’re already past their peak.” With negative effects like these, human health and agriculture will face hardship while moving forward.
This study further demonstrates how cruel climate change is to humans, plants and animals, reminding us how much we are all connected with the environment we share.
1. What did scientists find according to the study?| A．Some seasons will disappear in their tracks. |
| B．Global warming will be at its worst in 2100. |
| C．Climate change affects the days of summers. |
| D．Human health remains unharmed by climate change. |
| A．Add. | B．Extend. | C．Keep. | D．Shorten. |
| A．Mosquitoes can survive in more places. |
| B．The environment will change as we wish. |
| C．Human health and agriculture are hardly affected. |
| D．Some species are more able to adapt to the change. |
| A．Is the Earth getting warmer? |
| B．Is climate change bringing hardship? |
| C．Is mankind to blame for longer summers? |
| D．Is summer taking over from all other seasons? |
【推荐3】Researchers have successfully changed the blood type of a donated human lung by treating it with enzymes(酶) marking an important step towards making universal donor organs.
Blood types are largely defined by the presence or absence of certain sugar molecules (分子) called antigens(抗原) on the surface of cells. These can occur not just on the cells of the blood itself, but other tissues. If an antigen isn’t recognized by the body’s immune system, it will mount an attack on these cells. This leads to the rejection of transplanted organs from a donor with a different blood type.
People with the most common blood type, O, lack these antigens on their cells, so their organs can be accepted by people with other blood types. If all donor organs could be made type O, for example, the lungs from someone with blood type A, this could be beneficial.
To try this, Cypel and his team used a pair of enzymes in the human stomach to digest sugars. They found the enzymes could remove 97 percent of type A antigens in the lungs from a type A donor in 4 hours, which meant the cells had been effectively changed to blood type O.
After this treatment, the altered lungs were kept alive using a system known as ex-vivo lung perfusion (离体肺灌注), which supplies organs with nutritious fluid so they are ready for transplantation. To simulate a transplant, Cypel’s team added type O blood, which contains antibodies that would attack type A antigens, to the fluid supplying the lungs. The treated lungs had minimal antibody damage compared with untreated lungs.
Although cells rid of antigens tend to produce new ones over time, Cypel hopes the lack of antigens would last long enough for the body to get through the dangerous first few days and weeks after a transplant. The team now intends to test the procedure in animals. The study only looked at the effects of a simulated transplantation over the short term, which isn’t enough to assess whether the resurfaced antigens could eventually have a negative effect.
1. Which of the following may decide the blood type of a person?| A．Sugar. | B．Enzymes. | C．Antibody. | D．Antigens. |
| A．Type O is better than other blood types. |
| B．Type O is more accessible to researchers. |
| C．Organs with type O can be more acceptable. |
| D．Organs with type O can help digest antigens. |
| A．The blood type was temporarily changed. |
| B．Signs of severe rejection happened to them. |
| C．There was no effective way to keep them alive. |
| D．The enzymes were of little use in the treatment. |
| A．Practical suggestions for future study. | B．Detailed explanations of the findings. |
| C．Potential applications of the discovery. | D．Major limitations of the present study. |
【推荐1】Engineers at the University of California San Diego have developed a new method that doesn't require any special equipment and works in just minutes to create soft, flexible,3D-prnted robots.
The innovation comes from rethinking the way soft robots are built : instead of figuring out how to add soft materials to a rigid robot body, the UC San Diego researcher started with a soft body and added rigid features to key components. The strictures were inspired by insect exoskeletons,which have both soft and rigid parts — the researchers called their creations
“flexoskeletons (柔性外骨骼）”.The new method allows for the construction of soft components for robots in a small bit of the time previously needed and for a small bit of the cost.
“We hope that these flexoskeletons will lead to the creation of a new class of soft robots, ” said Nick Gravish， a mechanical engineering professor at the Jacobs School of Engineering at the UC San Diego and the paper ’ s senior author. “ We want to make soft robots easier to build for researchers all over the world. ”
The new method makes it possible to build large groups of flexoskeleton robots with little hand assembly (装配）as well as assemble a library of Lego-like components so that robot parts can be easily swapped.
Researchers detail their work in the April 7 issue of the journal Soft Robotics. The team plans to make their designs available to researchers at other institutions as well as high schools.
One flexoskeleton component takes 10 minutes to print and costs less than $1. Flexokeleton printing can be done on most low-cost commercially available printers. Printing and assembling a whole robot takes under two hours.
The final goal is to create an assembly line that prints whole flexoskeleton robots without any need for hand assembly. These small robots could do as much work as one massive robot on its own — or more.
1. What does Paragraph 2 mainly talk about?| A．The origin of the new method. |
| B．The function of the new method. |
| C．The advantages of the new method. |
| D．The cost of the new method. |
| A．Indifferent. | B．Skeptical. |
| C．Curious. | D．Hopeful. |
| A．Benefit moss students. |
| B．Produce a lot of flexoskeleton robots. |
| C．Build robots by hand. |
| D．Create many larger ones. |
| A．New Robos Made of Special Equipment and Materials |
| B．A New Method of Building Giant,Soft and Flexible Robots |
| C．Flexoskeletons Make Soft Robots Faster and Cheaper to Make |
| D．Flexoskeletons Create Lots of Soft Robots with Hand Assembly |
【推荐2】Amazon wants to be able to answer the troublesome question: Did I leave the stove on? The latest home security tool by Ring, a home security company owned by Amazon, is the Always Home Cam, a flying drone that can help homeowners check their apartments whenever they’re not in.
The Always Home Cam is a lightweight, self-docking, flying indoor camera that can take a predetermined path set by its user. When used with Ring’s proprietary home alarms systems like the Ring Alarm, the Always Home Cam will take flight and check the house for any potential disturbances. The drone unit can also be controlled remotely and manually. After a flight, the Always Home Cam automatically returns to its station itself for charging. It only records while in flight, too.
You can ask it to fly to check the stove while you’re out, or to see if you left the windows open. It’s also great for checking on naughty pets. The drone has obstacle avoidance technology built-in, and hidden propellers(螺旋桨) to mitigate any damage to household furnishing in the event of a collision. Amazon says the drone will automatically take flight if there’s movement in the house to show you what’s going on.
The device was one of several that Amazon unveiled Thursday as part of its annual appliance event. Due to the pandemic, this year’s version was held online instead of at Amazon’s Seattle headquarters.
The indoor flying camera, called the Ring Always Home Cam, still needs approval from the U.S. Federal Communications Commission, but Amazon said it expects to sell it next year at $250. It will also launch a camera and alarm system for cars next year under its Ring brand.
Critics have raised privacy concerns about Ring, which is best known for its doorbell cameras, citing the company’s close relationship with police departments. Amazon said the drone only records when it is in the air, and that it makes a sound when it flies so any people in the house knows its recording.
1. What’s the main idea of the text?| A．The Always Home Cam can ensure your safety. |
| B．Always Home Cam can guard your house while you out. |
| C．Critics raised privacy concerns about the Always Home Cam. |
| D．New devices were unveiled on Amazon’ annual appliance event. |
| A．It can take a path set by computer. | B．It can record when you are out. |
| C．It can get charged by itself. | D．It can take flight at any time. |
| A．It was unveiled at Amazon’s Seattle headquarters. |
| B．It will be sold at $250 next year. |
| C．It can lessen damage to furniture for its obstacle avoidance technology. |
| D．It records in the air, not found by anyone. |
| A．Favorable. | B．Critical. | C．Doubtful. | D．Objective. |
【推荐3】At 6.00 p.m. on Thursday, in Waterstones in Piccadilly, London, staff (全体雇员) were running around with bowls of jellybeans and bottles of lemon juice. Five minutes later, people of all ages started to come through the doors. Some dressed up as characters from the books! “This is the third event I’ve been to,” said 28-year-old Alex. “Last year they changed the second floor into Diagon Alley.” In many of the chain’s 275 branches across the UK, similar scenes were taking place. “Our first wizards (巫师) have arrived for Harry Potter night,” said staff at the Bradford store.
But Harry Potter night wasn’t the only cause for celebration for staff and customers. The previous day, Waterstones had announced that it was back in profit for the first time since 2011, under the leadership of its very own wizard. James Daunt. Daunt was already a successful bookseller. He was brought in to rescue the Waterstones chain when it was about to close down.
When Daunt took over Waterstones, his first task was to cut costs. Then he had to make the stores more attractive and improve the lighting. Coffee shops were opened inside the stores, and events were held, such as the now-famous Harry Potter nights, or talks by authors. But the biggest change was that Daunt gave each store the power to choose what books to sell, and to choose the prices for different books. This made a big difference. Sales went up because shops were storing more books that interested local customers.
Daunt is confident about the future of bookshops. “People love buying books,” he said. “It’s a physical pleasure that customers don’t get when they shop online. If we keep creating shops that do that, it doesn’t matter what goes on online. High streets and shops are part of the heart of the community. People will always want to go to shops.”
1. Why did people come to Waterstones in Piccadilly on Thursday?| A．To buy the Harry Potter books. | B．To attend a Harry Potter night. |
| C．To meet the author of books. | D．To look around Diagon Alley. |
| A．A wizard was visiting the store. | B．The chain started to make money. |
| C．The bookshops would open again. | D．James Daunt became the owner. |
| A．Making stores smaller. | B．Choosing the books himself. |
| C．Giving stores more freedom. | D．Selling books to local customers. |
| A．They provide cheaper books for people. |
| B．Online shopping will not last forever. |
| C．They can recommend suitable books. |
| D．They provide what online booksellers cannot. |
