Baby seabirds that have not yet hatched communicate with their siblings (兄弟姐妹) in neighboring eggs by vibrating (震动) their shells (蛋壳), scientists have discovered.
A study of yellow-legged gulls revealed one of the known examples of embryo-to-embryo communication. When exposed to the alarm calls of an adult bird responding to a dangerous predator, developing chicks apparently were able to convey the presence of danger to their nest mates by vibrating inside their eggs.
The team collected 9 yellow-legged gull eggs from Sálvora Island and sorted them into nests of three. When the eggs were six days off hatching, two of the three eggs in each nest were temporarily removed from the nest and exposed to either a recording of a predator alarm call or white noise each day until the chicks hatched. The noise was delivered four times a day at random for three minutes at a time. The third egg from each group remained in the nest.
It was found that the embryos in the shells responded to the external alarm calls by vibrating and sounding less, and that this message appeared to be passed on to the third nestmate. It was seen to copy the vibrations. It experienced genetic changes and had an increase in the production of stress hormones (荷尔蒙) as well.
“This kind of communication—embryo to embryo—can generate developmental changes that can have potential benefits to the birds after hatching,” said Noguera, the lead author of the study.
A rise in stress hormones makes birds more aware of their surroundings after hatching. When hatched chicks were exposed to alarm sounds, it was found that those who had listened to the noises previously in the eggs were quicker to run away and hide.
Noguera said the phenomenon was likely to occur in other bird species. His team now plans to investigate whether the chicks are able to pick up other clues about their external environment before hatching, such as how many other eggs are in the nest.
1. What do the unhatched birds mean to do by vibrating shells?| A．Fight with a predator. | B．Play with their nest mates. |
| C．Seek care from adult birds. | D．Warn others of danger. |
| A．The theoretical base of the experiment. | B．The subjects of the experiment. |
| C．The process of the experiment. | D．The findings of the experiment. |
| A．The presence of danger. | B．The external environment. |
| C．The third egg in the nest. | D．The embryo-to-embryo communication. |
| A．It makes them mature earlier. | B．It helps them adapt to life after hatching. |
| C．It allows them to develop physically. | D．It strengthens bonds with their siblings. |
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【推荐1】Sucking blood is a risky business. At least for the female mosquitoes that need these nutrients to nurture their developing eggs. Not only do these bugs have to find a suitable blood donor, but once they’ve had their fill, they have to be able to escape undetected—to avoid the big swat. How they finesse this stealthy departure has just been revealed in the Journal of Experimental Biology.
Feasting(饱餐) on an unsuspecting mammal can double a mosquito’s body mass. So how does a fully loaded female heave that added bulk off the skin of her host without triggering its pressure sensors and bringing on that fateful slap? To find out, Florian Muijres of Wageningen University in The Netherlands and his colleagues used cameras that record 13,500 frames per second to capture the takeoff maneuvers of 63 blood-fed malarial mosquitoes.
What they discovered is, when it comes to a soft yet speedy getaway...for female skeeters, the wing’s the thing. With a wingbeat frequency of about 600 beats per second...the insects are able to lift themselves lightly off their host. That approach is the opposite of the one favored by most other winged things, says Muijres.
“When most flying animals when they take off, like birds or a fly for example, they first use their legs to push off very hard, and then when they are in the air, then they start beating their wings and generate aerodynamic lift(气动升力) to be able to fly away. Mosquito does it the other way around. It first starts beating its wings and through the aerodynamic forces these wings generate, their body is being lifted off from the substrate. And then they do gently also push down with their long legs to be able to further power their liftoff. But these forces that are being generated by the legs are relatively small.”
In fact, the faint flutter of a mosquito’s wings produces less than one third of the force exerted by similar-sized but much less subtle fruit flies as they shove off in search of another banana. And even on a full stomach, these bloodsuckers are stunningly fast, says Muijres. “So takeoff phase takes only about 30 milliseconds, which is 10 times faster than how fast we can blink our eye.” And they’re gone before we know what hit us. And before we can hit them.
1. What does the passage mainly talk about?| A．How mosquitoes get nutrients for their developing eggs. |
| B．How mosquitoes can find their suitable blood donors |
| C．How mosquitoes escape undetected after sucking blood. |
| D．How the female mosquitoes find their perfect partners. |
| A．Their legs | B．Their ears | C．Their mouths | D．Their wings |
| A．mosquitoes are lighter than them | B．mosquitoes are keen on sucking blood |
| C．mosquitoes take off first with wings and then legs | D．mosquitoes take off through the aerodynamic forces |
| A．extremely fast | B．equal to that of our blink |
| C．faster than that of fruit flies | D．greatly affected by their full stomach |
| A．eggs | B．blood | C．mosquitoes | D．bugs |
| A．extra weight from sucking blood |
| B．an unsuspecting mammal |
| C．a fully loaded female |
| D．her host |
【推荐2】In most parts of Britain, the black cat is a symbol of good luck and owning a black cat may bring good luck to the family. But recently, black cats can no longer enjoy so much favor.
The Royal Society for the Prevention of Cruelty to Animals (英国防止虐待动物协会) announced a rise in the number of black cats being abandoned by their owners, due to not looking good in selfies (自拍). According to the RSPCA, more than 70 percent of the cats in its care are black. The biggest reason for that is black cats tend not to photograph as their lighter and brighter-colored fellows with more obvious markings. An RSPCA spokesman said, “This has become a national problem. And we are urging people to never judge a cat by its color but look at its personality instead.”
The Millwood Cat Rescue Centre has taken in nice black cats in the past two weeks. The founder of the rescue centre said, “We have had a lot of black cats because people don’t like black at the moment. Other look at the black cats and then just say ‘Oh, have you got anything else?’”
Animal lover Gabriella Fletcher owns a 16-year-old black cat, Susie. She regularly takes selfies with her pet. She said, “It is hard to get a good picture as you can’t really see how beautiful Susie is. She is just as special as any other cat.”
1. Why are black cats less favored by people?| A．They are rising in number. | B．They don’t bring good luck anymore |
| C．They are banned by RSPCA. | D．They don’t look good in photos. |
| A．People want more black cats. | B．People want to have something to eat. |
| C．People want more pet animals. | D．People are unwilling to see so many black cats. |
| A．disgusting | B．unlucky |
| C．ordinary | D．attractive |
| A．Black cats out in “selfies”. | B．Black cats abandoned in the UK. |
| C．Black cats in need of caring. | D．Black cats favored again. |
【推荐3】Dozens of dolphins swam out of the polluted waters of Haifa Harbor on Tuesday. This was the first time that dolphins had visited this crowded Mediterranean Port, and researchers were surprised by the unexpected event.
Between 40 and 50 of the dolphins appeared in the busy port on Tuesday morning, obviously drawn by the fish-rich waters of Haifa Bay.
However, the bay is also full of harmful chemicals. Aviad Sheinin, professor of Haifa University’s Maritime Studies Department, said he didn’t think the dolphins were harmed by the pollution, but that he hoped they would swim back to the sea soon. “It seems that they are quite relaxed. They don’t seem to be stressed, ”he said.
Haifa Bay is lined by chemical companies that have been pouring poisonous waste into the water for decades. While pollution levels have dropped in recent years, the water is still considered a health hazard(隐患).
“There are lots of fishes in Haifa Port. Unfortunately, we couldn’t tell the dolphins that the fish are not healthy, and I don’t know what the result will be,” he told Israel Army Radio.
Hundreds of Haifa residents gathered around Haifa Bay to see the interesting sight, and researchers said this provided a rare chance to film and study the rough-toothed dolphins. In addition to the dozens of dolphins which swam into the port on Tuesday, a similar number stayed outside the breakwater (防波堤). Later Tuesday the dolphins left the port but remained near the entrance and Israel’s coastguard was patrolling (巡逻) the area to try to make sure the dolphins didn’t re-enter the poisonous waters.
Relatively little is known about rough-toothed dolphins, which are usually found in deep and warm tropical waters.
1. Which of the following reason makes Haifa Bay full of harmful chemicals?| A．unhealthy fish | B．ships |
| C．chemical companies | D．residents living nearby |
| A．he is curious about the dolphins |
| B．the dolphins might affect the existence of fish in Haifa port |
| C．he will do research on the dolphins |
| D．he is uncertain about what will happen to the dolphins |
| A．protect the dolphins from the polluted waters |
| B．avoid traffic jam |
| C．deal with the harmful waters |
| D．prevent people killing dolphins |
| A．dolphins are well protected in Israel |
| B．Haifa Bay is full of harmful chemicals |
| C．dolphins made a surprise visit to the polluted harbor |
| D．people love dolphins |
【推荐1】A family’s socioeconomic status (SES) affects more than just their lifestyle , and it can also impact the intellectual development of children as early as 18 months old . Researchers Betty Hart and Todd Risley identified what they call “ The 30 Million Word Gap ” , which shows that children in higher income families will hear approximately 30 million more words than children in families on welfare by the time they are three years old . The researchers found that these discrepaneies are even visible in children’s brain scans . And this gap doesn’t just disappear after age three : hearing additional words so early in life leads to higher IQs and more academic success later . More recently , the result has been reconfirmed by the LENA Foundation , a non-profit organization .
Todd Risely , co-author of the study , emphasized that being born into a low SES family does NOT prevent a child from realizing his or her full potential or from competing with children from higher socioeconomic status families , especially if a parent or caregiver , such as a grandparent , engages in daily and frequent intelligent interaction with the child during the critical first three years of life ; being born into a high ESE does NOT assure that a child will realize his or her full potential , especially if child-raising is outsourced to a nanny who does not have active interaction with the child during the first three years .
“ Language is like nutrition for your brain . The more words you hear , the more your brain develops , ” Betty Hart said . “ If you don’t have language , you can’t progress . Language is the key . ” Based on the research , several pilot programs designed to help parents get into the habit of talking with their babies , a practice that scientists say can do wonders for a child’s future literacy are being set up .
1. The underlined word “ discrepancies ” possibly means __________ .| A．similarities | B．possibilities | C．differences | D．difficulties |
| A．Todd Risley has a disapproving attitude towards the research . |
| B．The research result does not necessarily apply to specific situations . |
| C．Attention shall be attached to the accumulation of spoken words after 3 . |
| D．A grandparent is considered as a better caregiver than a part-time nanny . |
| A．language is crucial to develop babies’ future academic performance |
| B．more talks are recommended to improve babies’ reading ability . |
| C．the higher the SES is , the more intelligent the child will be |
| D．relevant measures should be taken to help develop babies’ brain |
| A．SES Is the Key to Babies’ Future |
| B．High SES Leads to Future Success |
| C．Parents Impact Babies’ Development |
| D．More Talks Benefit Babies’ Development |
【推荐2】Daylight-powered germ-killing equipment（杀菌设备）may someday help protect health workers from deadly virus like Ebola virus. That is a finding from a study published in the journal Science Advances.
Study organizers say they’ve developed membranes（薄膜）that produce very small amounts of hydrogen peroxide（过氧化氢）when left in daylight. Membranes are thin plastic, structures that can serve as barriers. They let some things pass through, but other things art blocked. Hydrogen peroxide, a liquid sold in drug stores, works as a disinfectant（杀菌剂）.
Nearly 500 health workers were infected and died in 2014 when Ebola spread through parts of West Africa. Caregivers wear full-body protective suits when they come into contact with patients with infectious diseases. But the process of removing the suits is a time when infection can spread if the surface is covered with virus. “If there’s any live bacteria or virus on the surface, it’s still transmissible and could cause infection,” said Gang Sun of the University of California. He is one of the researchers that worked to develop membranes that could cover the outside of protective equipment.
When the chemical molecules（分子）on the surface of these membranes are put in sunlight, they react with oxygen in the air to produce small amounts of hydrogen peroxide. Gang Sun explains that the process creates less hydrogen peroxide than what you would use to remove dirt on clothing, for example. But it is still enough to kill organisms.
Rohan Tikekar is a food scientist with the University of Maryland. He described the development as “quite novel,” or new and different, Tikekar was not involved with the recent study. He said others have developed materials that produce disinfecting chemicals. But most only work under high-energy ultraviolet（U V）light, and not usual daylight. The new membrane also works in the dark for at least an hour or two because of chemical properties that can recharge its germ-killing powers. Tikekar called that an important improvement.
Gang Sun said the new membranes, though still Far from perfect could be used for things other than protective equipment for health workers. They could also be added to packaging for fruits and vegetables to keep foods fresher and reduce the risk of being polluted. Some versions of the material use natural chemicals’ Sun says that one of the next steps is to make it safe to sat
1. Which of the following statements is TRUE according to the passage?| A．Daylight helps to turn thin plastic barriers into germ-killing material. |
| B．Gang Sun developed membranes alone because he was infected with Ebola, |
| C．Hydrogen peroxide can kill live bacteria as it is a liquid. |
| D．The membranes react with oxygen when pat in sunlight. |
| A．Cautious. | B．Favorable. |
| C．Doubtful. | D．Critical. |
| A．The importance of the new membranes. |
| B．The drawback of the new membranes. |
| C．More probable uses of the new membranes. |
| D．More influences of the new membranes. |
【推荐3】The unusual day of February 29 comes up on the calendar only every four years. In American English, February 29 is called a leap day. And the entire 12-month period with a February 29 in it is called a leap year. The year 2020 is such a year.
As a verb, the word “leap” means to jump, or to move quickly. “Leap” can also be a noun, meaning a jump or a sudden move. In a leap year, the dates jump over one day of the week. In 2017, the last day of the year December 31, fell on a Sunday. In 2018, it fell on a Monday. In 2019, it fell on the Tuesday. But in 2020, December 31 will fall on a Thursday. It just leaps right over Wednesday. “Leap” is also an important word for two American expressions. One is a kind of warning. If you want someone to investigate a situation completely before taking action, you might say “look before you leap”. The other expression is a phrase of hope. Urging someone to “take a leap of faith” invites the person to take action, even if not everything about a situation is known.
Interestingly, both phrases are completely reasonable to say to someone who is about to get married.
On that note, some people choose to marry on February 29 because it is an unusual day. But some ancient people would likely tell couples not to do it. Leap years were believed to be difficult, and leap days were unlucky and a bad time to begin anything new.
Whatever you think about them, the changes in the calendar will be gone soon enough. Then we can return to normal, and leap over February 29 as usual.
1. If December 31, 2121 is Wednesday, what day is December 31, 2124?| A．Thursday. |
| B．Friday. |
| C．Saturday. |
| D．Sunday. |
| A．When you encourage someone to take action. |
| B．When you advise someone not to hold a wedding. |
| C．When you warn someone not to make a decision quickly. |
| D．When you want someone to investigate a situation carefully. |
| A．They were good days to try new things. |
| B．They were normal days in leap years. |
| C．They were a bad time for getting married. |
| D．They were a good time for moving house. |
| A．Lucky Days for Couples |
| B．Leap Days and Leap Years |
| C．The Changes in the Calendar |
| D．The Importance of February 29 |
【推荐1】Some of the greatest scientists of all time are women who have made important discoveries in a variety of fields in science. Several of their contributions throughout history are even more than men’s contributions. Our list of the most famous female scientists below are organized in order of popularity so you can read about the advancements that they made.
Marie Curie (1867-1934)
Famous For: Work on radioactivity
Marie Curie was the first woman to win the Nobel Prize and the only woman to win this award in two fields: Physics and Chemistry. She discovered polonium and radium and her work helped with the creation of X-rays.
Jane Goodall (1934)
Famous For: Primate (灵长类) studies
Jane Goodall is known world-wide for her groundbreaking studies on primates. She is considered as the top expert on chimps in the world and is perhaps best known for her 45-year study on the social lives of these animals in Tanzania.
Rita Levi-Montalcini (1909-2012)
Famous For: Nerve growth studies
Rita Levi-Montalcini was a neurologist (神经病学家) who won the Nobel Prize in Physiology or Medicine in 1986 for her findings in Nerve Growth Factor (NGF). She was the first Nobel Prize winner to live past her 100th birthday.
Lise Meitner (1878-1968)
Famous For: Work on radioactivity and nuclear physics
Lise Meitner was a key member of a group that discovered nuclear fission (裂变). One of her colleagues, Otto Hahn, was given the Noble Prize for this work. That Meitner didn’t get the award is considered to be a huge error by the Nobel committee.
1. Who is still contributing to the world?| A．Marie Curie. | B．Jane Goodall. |
| C．Rita Levi-Montalcini. | D．Lise Meitner. |
| A．Nerve growth. | B．The wildlife. |
| C．Nuclear explosion. | D．Radioactivity. |
| A．She was awarded the Nobel Prize. |
| B．She made a big mistake in her work. |
| C．She did lots of studies about nerve growth. |
| D．She made great contributions to nuclear physics. |
【推荐2】Extreme athletes have been using wingsuits（翼装）to fly for many years. However, the pull of gravity makes it impossible to speed up or fly higher. To push past the limitations, Peter Salzmann teamed up with German car maker BMW. The result is an electrified wingsuit, which allows flyers to rise to higher altitudes at the speed of up to 186 miles per hour!
The 33-year-old professional wingsuit pilot first thought of creating the design in 2017, "At the time, I was developing suits for skydiving with a friend," he explains. "One evening after a day of testing, we threw out lots of ideas about how we could improve performance. One of them was a supporting motor-and it's an idea I just couldn't shake off. I found the idea of being able to jump from my local mountain wearing the wingsuit and land in my garden exciting."
To help with the process, Salzmann reached out to the experts at BMW's Designworks Studio. It took the team three years and multiple test jumps to perfect the design. The result is an updated version of wingsuit with two 5-inch propellers（螺旋桨）, Powered by a battery, the propellers can be controlled using an on/off switch and even stopped mid-flight using the emergency button, if the flyer encounters an airplane or a flock of birds.
On November 6, 2020, Salzmann, wearing his hi-tech suit, leaped from a helicopter from an altitude of 10,000 feet to soar around the mountain peaks. The expert pilot fired up the electric motors and rocketed forward, gliding above four mountain peaks. The task completed, the pilot opened his parachute（降落伞）and gently landed.
It is unclear if Salzmann and BMW plan to make the electrified wingsuits available to the general public. But, one can always hope!
1. What do we know about the new wingsuit?| A．It flies faster and higher. |
| B．It breaks away from gravity. |
| C．It's equipped with a car motor. |
| D．It has been used for many years. |
| A．What Salzmann's friend did to help him. |
| B．What Salzmann experienced in his career |
| C．How Salzmann became a professional pilot. |
| D．How Salzmann came up with the new design. |
| A．Press the emergency button. | B．Reach out to an expert. |
| C．Check the propellers. | D．Open the parachute. |
| A．Explore. | B．Search. | C．Fly. | D．Dig. |
【推荐3】Are you afraid of moving up to senior high school? It is a completely new experience, but you shouldn't worry. We've got a guide to help you. You're not alone.
Remember that everybody else in your year is in the same boat. You may not notice it, but they're just as nervous as you are.
Moving to senior high school is a chance, not a problem. Things are different, and all you need to do is be polite and learn the new rules. The teachers will help you.
If you don't know what to do or are worried about something, then ask for help. Teachers are probably the best people to turn to, because they have experience in helping new students. Pay attention to what your teachers say. Everything changes.
There are lots of differences between junior high school and senior high school. You will have your lessons with different teachers in different rooms. You will have homework for different subjects on different days, so make sure you get organised.
Make sure you know which rooms your classes are in and which days you have your different subjects on.
If you've got an older brother or sister at the school, then ask them for advice.
Be yourself! It sounds simple, but things will become better if you just act naturally.
Having early nights makes a difference. You'll also find it easier to get up in the morning!
1. The author says that you're not alone, because other students ______.| A．are polite and friendly | B．will help you if possible |
| C．feel the same as you do | D．will learn the new rules with you |
| A．Just act naturally. | B．Don't be shy. |
| C．Change yourself. | D．Pay attention to others. |
| A．tell students about a new experience |
| B．help students that are going to senior high school |
| C．tell students how to make full use of time |
| D．teach students how to organise themselves. |
