It is easier to float in the ocean than it is to float in a swimming pool. Do you know why？
Ocean water is full of salt—and salt water can hold up more weight than fresh water. See for yourself！
You Will Need：
3 cups of warm water
·Measuring cup（量杯）
·Wide-mouthed jar
·Salt
·Spoon
·Raw（生的）potato
You Will Do：
1. Pour 1. 5 cups of warm water into the jar.
2. Add 1/3 cup of salt.
3. Stir（搅拌）until the salt is completely
dissolved.
4. Add another 1. 5 cups of water. Pour it slowly over the spoon into the jar so that the two liquids will not mix together.
5. Gently place the potato into the jar. Do not drop it.
What Will Happen:
The potato will sink—but only halfway!
Why?
Salt water is heavier than fresh water，so it will stay on the bottom. The fresh water will remain on top.
The potato is heavier than the fresh water, but it is lighter than the salt water. That is why the potato will sink halfway down.
1. In which step of the experiment do you add the salt？| A．Step 1. | B．Step 2. |
| C．Step3. | D．Step4. |
| A．Add the salt to the water. |
| B．Stir the salt in the water. |
| C．Place the potato into the jar. |
| D．Pour warm water into the jar. |
| A．It is easier to see what you are doing. |
| B．It pushes the fresh water to the bottom. |
| C．It will keep the water from coming out. |
| D．It will keep the liquids from mixing together. |
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【推荐1】If you have the strange feeling that you’ve read this before, don’t be alarmed. It’s probably just déjà vu. Déjà vu is the strange feeling that you’ve experienced something before, while at the same time knowing that you haven’t. You visit a friend’s apartment and have the overwhelming sense you’ve been here before, but that can’t be the case. This is the first time you’ve ever visited this city. Still, the feeling may be so real that you almost know what you’ll find when you walk into the kitchen.
Experts estimate roughly two out of three people have had the experience at least once. The experience typically lasts no more than a few seconds and there’s no warning of when it’s about to happen, making it extremely difficult to study. Much that is known about déjà vu is based on surveys. Still, researchers have come up with novel ways to study it in the wild.
Anne Cleary, professor of cognitive psychology and memory researcher, used virtual reality (VR) to trigger (引发) déjà vu. Cleary and her team took subjects through a series of scenes in the video game, carefully designed so that the spatial layout (空间布局) of one scene was similar to another, even though the actual images were quite different. The subjects experienced déjà vu when a scene was similar to one they’d seen before, suggesting that a similarity in spatial layout between two places might lead to a déjà vu-like sense of familiarity in a novel place.
“There may be many different reasons that could all be true for why déjà vu can happen,” Cleary says. Though no one has yet explained what causes déjà vu, it’s a good thing that science finally got serious about studying the strange phenomenon. “I think déjà vu research has been shedding light on processes that are helping us to understand memory better at a wider level than just trying to understand déjà vu,” says Cleary.
1. Why does the author mention “visiting a friend’s apartment” in paragraph 1?| A．To draw a comparison. | B．To make an assumption. |
| C．To present a fact. | D．To illustrate a concept. |
| A．Uncontrollable factors. | B．Unproven surveys. |
| C．Subjects’ mental state. | D．Similar spatial layout. |
| A．She compared similar scenes with the subjects. |
| B．She guided the subjects through a novel place. |
| C．She applied virtual reality to trigger déjà vu. |
| D．She depended on surveys to learn about déjà vu. |
| A．The accurate causes of déjà vu. | B．The phenomenon of déjà vu. |
| C．The significance of déjà vu research. | D．The procedure of déjà vu research. |
【推荐2】An experiment published in iScience provides evidence that octopuses (章鱼) feel pain like humans do.
During the experiment, Crook, who comes from San Francisco State University, placed an octopus between two rooms with different lines and spots on the walls, and then observed where she preferred to stay. The next day, in another part of the lab, Crook put acetic acid into one of the octopus’s arms. She says doing so is like pouring lemon juice on a paper cut. When the animal awoke with an aching arm, Crook kept her in the room she had preferred before. The researcher removed the octopus 20 minutes later and used lidocaine to numb (使麻木) her arm. Crook then placed her in the room she had not liked as much at first. After another 20 minutes, Crook returned her to her home container.
Finally, about five hours later, Crook brought the octopus back to the rooms and gave her an alternative: return to the originally preferred room, where she was kept with an aching arm, or go to the one she had not liked as much but where she was numb. Crook ran the experiment with seven octopuses. They all chose to go to the non-preferred room. As a control, Crook put salt water into seven other octopuses. Unlike the experimental group, those octopuses returned to their originally preferred room.
It turned out the octopuses related the room they had once liked better to the ache they felt the last time they were there. Then they compared that experience with their typical pain-free state and decided that how they usually felt was better. Using that information, the octopuses chose to go to the non-preferred room. “There’s a lot of brain processing that has to happen,” Crook says.
Crook’s study suggests that there should be more focus on the welfare of octopuses. Due to people’s ignorance, animals like octopuses are not properly protected in both research and industry in the U.S. Luckily, Crook’s findings, giving us more insights into them, have led to increased protection for octopuses.
1. What effect did lidocaine have on the studied octopus?| A．Keeping her awake. | B．Making her energetic. |
| C．Making her feel less pain. | D．Removing her memory of pain. |
| A．Treat. | B．Choice. | C．Lead. | D．Punishment. |
| A．They tend to work in groups. | B．Their preference changes with time. |
| C．They update their memories regularly. | D．Their painful memories last for hours. |
| A．The significance of the research. | B．The description of the research. |
| C．The reasons for protecting octopuses. | D．The assumption about the octopuses. |
【推荐3】“I’ve never met a human worth cloning，” says cloning expert Mark Westhusin from the cramped confines of his lab at Texas A&M University. “It’s a stupid endeavor.” That’s an interesting choice of adjective, coming from a man who has spent millions of dollars trying to clone a 13yearold dog named Missy. So far, he and his team have not succeeded, though they have cloned two calves and expect to clone a cat soon. They just might succeed in cloning Missy later this year — or perhaps not for another five years. It seems the reproductive system of man’s best friend is one of the mysteries of modern science.
Westhusin’s experience with cloning animals leaves him vexed by all this talk of human cloning. In three years of work on the Missyplicity project, using hundreds upon hundreds of canine eggs, the A&M team has produced only a dozen or so embryos carrying Missy’s DNA. None have survived the transfer to a surrogate mother. The wastage of eggs and the many spontaneously aborted fetuses may be acceptable when you’re dealing with cats or bulls, he argues, but not with humans. “Cloning is incredibly inefficient, and also dangerous，” he says.
Even so, dog cloning is a commercial opportunity, with a nice research payoff. Ever since Dolly the sheep was cloned in 1997, Westhusin’s phone at A&M College of Veterinary Medicine has been ringing busily. Cost is no obstacle for customers like Missy’s mysterious owner, who wishes to remain unknown to protect his privacy. He’s plopped down $3.7 million so far to fund the research because he wants a twin to carry on Missy’s fine qualities after she dies. But he knows her clone may not have her temperament. In a statement of purpose, Missy’s owner and the A&M team say they are “both looking forward to studying the ways that her clone differs from Missy.”
The fate of the dog samples will depend on Westhusin’s work. He knows that even if he gets a dog viably pregnant, the offspring, should they survive, will face the problems shown at birth by other cloned animals: abnormalities like immature lungs and heart and weight problems. “Why would you ever want to clone humans，” Westhusin asks, “when we’re not even close to getting it worked out in animals yet？”
1. Which of the following is TRUE about animal cloning?| A．Few private cloning companies could afford it. |
| B．Few people have realized its significance. |
| C．An exact copy of a cat or bull can be made. |
| D．It is becoming a prosperous industry. |
| A．Mr. Westhusin is going to clone a dog soon |
| B．scientists are pessimistic about human cloning |
| C．human reproductive system has not been understood |
| D．rich people are only interested in cloning animals |
| A．is stupid and should be abandoned |
| B．has been close to success |
| C．should be taken cautiously |
| D．is now in a dilemma |
【推荐1】For some people, certain foods can be deadly. Around the world, children are far more likely than ever before to develop food allergies（过敏）. In the US, for example, allergy rates among children were rising from 2010 to 2016, according to the Childhood Allergies in America report. It also showed that the number of children “at risk” for a severe allergic reaction rose by 104 percent. Almost half of these severe reactions were from food.
“In the past, children often were only allergic to one or maybe two foods. But now it’s very common to see children allergic to two or three or more foods,” said Hugh Sampson, a professor at the Icahn School of Medicine at Mount Sinai, New York City, US. “And milk, eggs, sesame, peanuts, tree nuts, fish and shellfish are the common ones to take the blame.”
First of all, as countries import exotic（外来的）products, people are more likely to adopt foreign diets. One example is an increased allergy to kiwis in the US. “Everything is so global now. We’re getting exposed to foods that we never had before,” Sampson said. “And as globalization accelerates migration, more people will tend to experience food allergies.”
Environmental factors may also play a large role: Migrants appear to show a higher possibility of food allergy and asthma（哮喘）in their adopted country in comparison to their country of origin, according to the BBC.
Changes in food making could explain the global rise in allergies as well. For example, people are more likely to be allergic to dry-roasted peanuts-common in the US, UK and Australia-than boiled or fried peanuts, which are common in China. This suggests that how and when the food is introduced is as important a factor as the food itself. Food allergy awareness has increased during recent years, but there’s more work to be done to understand and deal with its rise.
1. What does the second paragraph imply?| A．More foods today can lead to allergies. |
| B．Food was to blame for children’s allergies. |
| C．Kids are more likely to suffer allergies. |
| D．People all know the reasons for allergies. |
| A．Globalization has caused unexpected effects. |
| B．Globalization plays a role in increased allergies. |
| C．Globalization is the key to solving the problems. |
| D．Globalization allows people to experience more. |
| A．Optimistic. | B．Cold. |
| C．Concerned. | D．Disappointed. |
| A．Allergies increase globally. | B．How to get rid of allergies? |
| C．What causes your allergies? | D．Allergies matter a lot in life. |
【推荐2】Plastic is used to make a large number of products we use every day， such as drink and food containers，trash bags and grocery bags，cups and children's toys，and bottles for everything from mouthwash and shampoo to glass cleaner and dishwashing liquid. And that's not even counting all the plastic that goes into furniture， appliances， computers， and automobiles.
As the use of plastic has increased over the years，it's become a large part of America's solid waste﹣growing from less than 1 percent in 1960 to more than 13 percent in 2017. As an example of how and why plastic waste is increasing， the International Bottled Water Association reports that the US consumed 9. 67 billion gallons of bottled water in 2017， compared to 9.1 billion gallons the year before. The United States is the world's leading consumer of bottled water. A good first step in reducing plastic waste is switching to a reusable water bottle.
Recycling plastic reduces the amount of energy and resources （资源） needed to create plastic. Research shows that a bottle of water requires about 2，000 times as much energy to produce as the same amount of tap water. Recycling plastic products also keeps them out of landfills（垃圾填埋）and allows the plastic to be reused in making new products. Recycling 1 ton of plastic saves 7. 4 cubic yards of landfill space. And let's face it，a lot of plastic ends up directly in the environment，breaking down into tiny pieces ， polluting our soil and water.
Today，80 percent of Americans have easy access to a plastic recycling program. A universal numbering system for plastic types makes it even easier. According to the American Plastics Council， more than 1，800 US businesses handle plastic waste. In addition， over 200，000 grocery stores now serve as recycling collection sites for plastic waste.
1. What message does the first paragraph mainly intend to convey？| A．Plastic products are quite common. |
| B．Plastic is widely used in our daily life. |
| C．What functions plastic has. |
| D．Why humans make use of plastic. |
| A．plastic waste is on the rise in America |
| B．Americans prefer bottled water to tap water |
| C．plastic waste is the leading type of waste in America |
| D．using reusable water bottles doesn't help reduce plastic waste |
| A．It helps cut down on pollution. |
| B．It helps to make soil more rich. |
| C．It makes plastic easily broken down. |
| D．It produces new energy and resources. |
| A．Americans suffer a lot from plastic waste. |
| B．Americans are good at recycling plastic. |
| C．Recycling plastic is convenient in the US. |
| D．Recycling plastic brings great profits in the US. |
【推荐3】Located in the middle of the Egyptian desert is one of the Seven Wonders of the Ancient World, the Great Pyramid of Giza. Aside from being an incredible architecture achievement, it also serves as the final resting place for the great Pharaoh Khufu. Yet, one question which has confused archeologists and architects alike is how this amazing structure was built.
Many people don’t believe that humans were technologically advanced enough in ancient Egypt to build such a large and highly advanced structure. This brought about many crazy theories that the pyramids were constructed by a race of giants or even aliens from outer space.Another popular theory suggested that the pyramids were built by an army of poor slaves who were forced to.
Modern technology and some recent findings have helped shed some light on this ancient mystery. A major breakthrough occurred when an explorer accidentally uncovered a tomb containing some written information about the builders. The records reveal that the workers were paid and well-fed, and came from poor families in Egypt. Further analysis made it clear that people considered it an honor to work on the pyramids,and the builders were treated with great respect. In fact, anyone who died while working on the pyramids was given the honor of being buried in the tomb near where the pharaohs lay.
The myth that they purposely worked to death isn’t true, either. To avoid exhaustion, the builders worked three-month shifts and then were given a break to recover. A recent estimate from researchers is that a workforce of roughly 15,000 people could have completed the construction in about 10 years. An analysis of the bones of the builders revealed that their work was extremely tough, as most of the skeletons displayed signs of severe injuries. But thanks to their incredible effort, the human race has an astonishing monument that should stand the test of time.
1. Which of the following is true about the Great Pyramid of Giza?| A．It remains a mystery who built it. |
| B．It was a tomb for the Great Pharaoh Khufu. |
| C．It was one of the Seven Wonders of ancient Egypt. |
| D．It was an architecture wonder although roughly structured. |
| A．The identity of the Pyramids builders. |
| B．The well-off life the Pyramids builders led. |
| C．New information about the builders of the Pyramids. |
| D．Some information about the life of Pharaoh Khufu. |
| A．They were paid for their hard work on the pyramids. |
| B．They were eating well although they were from poor families. |
| C．They were selected because it was an honor to work on the pyramids. |
| D．They were buried near the pharaohs’ tombs if they died during working. |
| A．He is grateful that they could work so hard. |
| B．He shows great sympathy for their hard work. |
| C．He is impressed by their devotion to the Pharaohs. |
| D．He feels proud of them for their advanced technology. |
【推荐1】What is the most recognizable object in the world? Could it be a football or a big computer? No, the answer is a Coca-Cola bottle. Hundreds of millions of people can recognize a Coke bottle by its shape. Unlike any other famous commercial logo, the famous Coca-Cola logo has not changed in 100 years!
In 1886, John Pemberton, a druggist in Atlanta, Georgia, invented a new type of syrup (糖浆), using coca leaves, sugar and cola nuts, plus a few other secret ingredients. Pemberton sold it as a medicine; and with coca (the source of cocaine), it must have made people feel good! Nevertheless, Pemberton's medicine was not very successful, so he sold his secret formula (配方) to another druggist, Asa Candler, Candler was interested, because he had another idea; he thought that Pemberton's "medicine" would be much better if it was mixed with soda. Candler was thus the man who really invented the drink Coca-Cola. At first he sold it in his drugstore; then he began selling the syrup to other drugstores, where it was used with their soda fountains. Candler also advertised his new drink, and soon people were going to drugstores just to get a drink of Coca-Cola. Before long. other people became interested in the product, including a couple of businessmen who wanted to sell it in bottles. Candler sold them a license to bottle the drink, and very quickly the men became millionaires. Then in 1916 the famous bottle, with its very distinctive shape, was designed.
During the First World War (1914-1918), American soldiers in Europe began asking for Coca-Cola, so the Coca-Cola company began to export it to Europe. It was so popular with soldiers that they then had to start bottling the drink in Europe. Today. Coca-Cola is made all over the world, including Russia and China; it is the world's most popular drink.
As for the famous formula, it is probably the world's most valuable secret! The exact ingredients for making Coca-Cola are only known to a handful of people. And as for the coca that was in the original drink, it was removed in 1903, for it was a dangerous drug. Today's Coca-Cola contains caffeine, not cocaine!
1. What is the second paragraph mainly about?| A．The key ingredient of Coca-Cola. |
| B．The distinctive shape of Coca-Cola bottle. |
| C．The ever-changing logo of Coca-Cola. |
| D．The development of Coca-Cola. |
| A．John Pemberton. | B．Asa Candler. |
| C．An American soldier. | D．A couple of businessmen. |
| A．The formula of Coca-Cola is still a well-kept secret. |
| B．The ingredients for making Coca-Cola is of great value. |
| C．Coca wasn't removed from the drink until the First World War. |
| D．Caffeine has the same effect on patients as cocaine. |
| A．A biology textbook. | B．A life magazine. |
| C．A research paper. | D．A travel brochure. |
【推荐2】Most people aren’t good at creative problem solving for two reasons: (1) They are not trained in how to be creative. (2) They don’t understand group strength well enough to harness (驾驭) their power to maximize group creativity.
A key element of creativity is applying existing knowledge to a new problem. The more people getting involved in solving it, the more knowledge there is to work on it. Unfortunately, research shows that the traditional brainstorming methods fail to achieve that goal. When groups get together to exchange ideas, they actually come up with fewer ideas overall than if they each had worked alone.
To fix this problem, you should consider the two stages of group problem-solving: divergence (分散) and convergence (集中). Divergence happens when the group considers as many different potential solutions as possible. Convergence happens when the various proposed solutions are evaluated and reduced to a smaller set of candidate solutions to the current problem.
The essential principle of group creativity is that individuals working alone diverge, whereas group members working together converge. In groups, once a member states a potential solution, that makes others think about the problem similarly. That is why groups working together diverge less than individuals working alone.
Therefore, be aware of when to diverge and when to converge. For example, early in the problem-solving process, have group members work alone to write down statements describing the problem. Then get them back to discuss their descriptions. The group discussion will lead everyone to accept one or a small number of these statements to work on — this is healthy convergence.
When starting to generate solutions, you again want divergence. Have people work alone to start. Then collect people’s initial ideas and send them around to others and allow the divergence to continue as everyone individually builds on the ideas of other members.
Finally, let the group discuss the resulting ideas. This discussion will gradually lead the group to converge on a small number of candidate solutions.
This simple method works effectively, because it respects what individuals and groups do best.
1. According to Para. 4, when a member presents an idea, others tend to_____.| A．think the other way round |
| B．follow his way of thinking |
| C．be more confident in their own ideas |
| D．be less willing to share their own ideas |
| A．Discuss the problem. |
| B．Simplify the problem. |
| C．Put down group statements together. |
| D．Write down their individual descriptions. |
| A．By adding in collected evidence. |
| B．By reorganizing his own words. |
| C．By drawing on others’ ideas. |
| D．By making his statement briefer. |
| A．To advocate a way to make group thinking more effective. |
| B．To demonstrate the difficulty in organizing group thinking. |
| C．To highlight the differences between divergence and convergence. |
| D．To show the advantage of group thinking over individual thinking. |
【推荐3】An Atlanta mother is making her kids work hard for their money. Instead of giving them an allowance, Shaketha Marion McGregor is giving them actual job titles and duties. Her innovative idea that she posted on Facebook has been shared over 114,000 times.
In a selfie, the mother of three showed that she was now “hiring” for three positions laundry supervisor, lead housekeeper and kitchen manager for her company called “This Mom Means Business”. The photo also showed that she would be holding interviews for these jobs. The applicants? Her three kids Jahkeem, 13, Takeia, 10, and Serinity, 6.
McGregor said the interviews went smoothly. To her surprise, the youngest was the most professional. “Jahkeem almost laughed the entire time, which caused me to laugh a lot, too. It was tons of fun. His only questions were, ‘How much do I get paid? How often do I get paid? And do i have to pay tax?’”
The kids are handling the responsibilities of their new job duties pretty well so far, though it has only been about a week. McGregor says they’re anxiously awaiting their first paycheck. The mother said she came up with the idea after she had to replace a lot of items she lost during a tragedy. “We lost a lot of things last year in a house fire and I’ve been really working hard to recover the things that we need,” McGregor said And my kids continued to ask for things that they want so I figured it would be best to have them earn it.”
1. Why does the Atlanta mother conduct interviews?| A．To hire some people for her company. | B．To reduce her own pressure from work. |
| C．To let her kids earn money through labor. | D．To help her kids know how to save money. |
| A．The positions that may be applied for. | B．The way the kids do their duties. |
| C．How the kids get along with each other. | D．How the kids compete for the jobs. |
| A．Takeia. | B．Jahkeem. | C．Serinity. | D．Shaketha. |
| A．The father died in a tragedy. | B．They suffered a fire. |
| C．They have moved to a new city. | D．The family is very poor. |
