1 . The universal speed limit of any kind of wave — whether electromagnetic or gravitational travelling through a vacuum has been known since Albert Einstein developed his theory of special relativity in 1905. But the maximum speed of sound moving through a solid or a liquid has just been calculated for the first time. It is about 36 kilometre per second, more than 8,000 times lower than the speed of light in a vacuum.
To make this calculation, Kostya Trachenko at Queen Mary University of London and his colleagues started with two well-known physical constants: the ratio of proton mass to electron mass, and the fine structure constant, which characteristics the strength of interactions between charged particles.
Trachenko says we have a pretty good idea of these values, because if they were changed even a bit, the universe wouldn’t look at all like it does.” If you change these constants by a few percent, then the proton might not be stable anymore, and you might not even have the processes in stars resulting in the combination of heavy elements, so there would be no carbon, no life,” he says.
Sound is a wave that spreads by making neighbouring particles interact with one another, so its speed depends on the density of a material and how the atoms within it are bound together. Atoms can only move so quickly, and the speed of sound is limited by that movement.
“The common wisdom was that diamond has the highest speed of sound, because it is the hardest material, but we didn’t know whether there was a theoretical fundamental limit to it,” says Trachenko. The theoretical bound is about twice the speed of sound in a diamond.
The speed of sound is also dependent on the mass of the atoms in the material, so there searchers predicted that solid metallic hydrogen — a material that theoretically exists at the centre of giant planets, but for which laboratory evidence has been hotly questioned — should have the highest speed of sound. They calculated that it should be close to the theoretical limit. They also looked at experimental data for 133 materials and found that none of them broke the limit.
1. How did people find out the speed of waves?| A．By measuring the speed of sounds. |
| B．By using modern technology and science. |
| C．By depending on a great scientist’s theory. |
| D．By comparing the theories about the universe. |
| A．Interactions. | B．Particles. | C．Values. | D．Constants. |
| A．Diamond has surely the highest speed of sound. |
| B．He believes in a theoretical fundamental limit. |
| C．Solid and liquid materials have the same speed limits. |
| D．Diamond has yet to be proven the hardest material. |
| A．It has a close theoretical fundamental limit of speed. |
| B．There would be no carbon,no life in the universe. |
| C．Some materials broke theoretical fundamental limit. |
| D．It will surely travel to other sections of the universe. |
On a Saturday afternoon, my friend’s eleven-year-old daughter Jenny and I wound our way through the crowd at the State Fair of Texas. Her dad, along with my husband, followed behind. Seconds later, we arrived at the section of the fair that I dreaded（畏惧）more than searching for a place to park: the midway rides. As the loudspeakers shouted “I Will Survive”, potential victims passed us like a tornado.
Jenny looked up at the windsurf ride with her eyes wide open. I was confident that she, like my children when they were her age, would bypass the twisting, terrifying, multi-story mechanical arms and continue walking elsewhere.
I was wrong.
“Will you go on this ride with me?” she asked.
“Um, sure,” I answered while glancing up at the people who were suspended upside down.
“How bad could it be?” I asked.
“Not bad if rides don’t make you sick,” Jenny said.
I could have made up an excuse for not to risk my life. Or I could have admitted my possibility of motion sickness. But, earlier that morning, I had challenged myself to try something new each week. I was ready to push myself out of my comfort zone. Jenny stared at the ride, eager to experience the same thrill as the brave group of riders in front of us, I couldn’t say no.
We bought two tickets. After climbing into our seats, an attendant reached up, pulled down the bar, and locked it in place. The ride lifted us slowly and then turned us over like the blueberry pancakes. Staring at the ground directly below us, I wondered why I had decided to wear flip-flops（人字拖）. I wondered when my new health insurance would kick in. My stomach upset. The ride touched down finally. Her dad and my husband were waiting for us at the exit. “How was it?” they asked.
“Fine. No big deal,” I said, even though my head was dizzy. Jenny walked ahead of us and convinced me to keep taking chances and sample more rides.
注意：
（1）续写词数应为150左右；
（2）请按如下格式在答题卡的相应位置作答。
“Oh, look at the pirate ship!” she said.
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On the way to the car, I sent my son a video of me on the first ride filmed by my husband.
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3 . Steller or Northern Sea Lions are sometimes confused with California Sea Lions but are much larger and lighter in color. Males may grow to 11 feet in length and weigh almost 2,500 pounds.
Stellers are not often seen in bays or rivers. Steller pups are born on offshore islands from mid-May to mid-July and weigh 35—50 pounds.
The current population of Steller Sea Lions is about 40,000 along the entire Pacific coast. There is great concern about this species. The western Aleutian stock has dropped by 80 percent in the last 30 years. In 1997, the western stock in Alaska was listed as endangered.
| A．Steller Sea Lions eat a variety of fishes. |
| B．Reasons for this decline are not known. |
| C．The male has a thick neck and looks like a lion. |
| D．They spend about half their time on land and half in water. |
| E．Mothers stay with pups for one to two weeks before hunting at sea. |
| F．They forbid the killing, harming or disturbance of any sea mammal. |
| G．Females are much smaller, growing to 9 feet in length and weighing up to 1,000 pounds. |
4 . Harvest Days
Event Details
Harvest Days has returned bigger and better than ever. This family-fun event falls on 7th & 8th, October from 10:00 a. m. to 5:00 p. m. on Saturday and 11:00 a. m. to 5:00 p. m. on Sunday. This year’s event includes a two-day silent auction (拍卖), staged in the Firehouse. Bid (投标) on a variety of heritage pieces inspired by objects preserved in the museum’s collection. Also, up for bid are a variety of museum passes, experiences, art, wine, beer, and more. All the money will benefit the museum through the work of the Landis Valley Associates.
Tickets will be available at the front gate.
Used to celebrate the harvest of a year’s hard work, Harvest Days is Landis Valley’s oldest and largest family event. Come for demonstrations, exhibits, live music, and children’s activities. Taste varieties of apples and watch them become apple butter and drink. Witness wool go from sheep to clothes. Pick a pumpkin of your very own and then decorate it. All of these and more are packed into two fun-filled days.
This year’s event offers food demonstrations, such as apple butter, processing pork, bake oven and heart h cooking; craft demonstrations, such as coopering, blacksmith, leather, brooms, millinery, weaving, woodwork; craft sales, such as jams & jellies, potteries, soap, candles.
Food will be available for purchase on site. Free parking.
LOCATION: Landis Valley Village & Far m Museum
ADDRESS: 2451 Kissel Hill Road, Lancaster, PA 17601
CONTACT: 717-569-0401
1. Where will the money from the auction finally go?| A．To the bidders. | B．To the museum. |
| C．To the government. | D．To the villagers. |
| A．Adventure and exploration. |
| B．Celebration and education. |
| C．Presentation and advertising. |
| D．Entertainment and exchange. |
| A．There is no charge of parking. |
| B．Apple juice is served for participants. |
| C．It will be held on an open farm in Landies Valley. |
| D．Collection’s of Landis Valley Associates are for sale. |
5 . Two new residents in Aarwangen, a small village in Swiss, filed complaints with the village council about the constant ringing of cowbells. They asked for the cows’ bells to be
Long-term residents, and the village’s remaining farmers were
Cowbells have been used in rural Switzerland for centuries. They were once useful for
Over the past few decades, many new
This year’s battle is not the first time residents have
Next month, Aarwangen’s villagers will gather for a public meeting to vote on the
| A．marked | B．watched | C．fastened | D．removed |
| A．angry | B．proud | C．frightened | D．excited |
| A．effect | B．comment | C．attack | D．reliance |
| A．study | B．preserve | C．record | D．restore |
| A．counting | B．tracking | C．entertaining | D．feeding |
| A．catch | B．contact | C．spot | D．hear |
| A．Besides | B．Therefore | C．However | D．Meanwhile |
| A．instead of | B．thanks to | C．regardless of | D．according to |
| A．residents | B．researchers | C．tourists | D．pioneers |
| A．attracted | B．accustomed | C．opposed | D．devoted |
| A．thought over | B．gave up | C．put on | D．complained about |
| A．hoped | B．promised | C．ordered | D．refused |
| A．alive | B．asleep | C．ashamed | D．awake |
| A．future | B．number | C．tone | D．design |
| A．rise | B．continue | C．spread | D．return |
6 . Time is running short to address climate change, but there are possible and effective solutions on the table, according to a new UN climate report released in March.
Only swift, dramatic, and sustained emission (排放) cuts will be enough to meet the world’s climate goals, according to the new report from the Intergovernmental Panel on Climate Change (IPCC), a body of climate experts that regularly summarize the state of this issue.
“We are walking when we should be running fast,” said Hoesung Lee, IPCC chair, in a press conference announcing the report in March. To limit warming to 1.5℃ above preindustrial levels, the target set by international climate agreements, annual greenhouse-gas emission will need to be cut by nearly half between now and 2030, according to the report. It calculates that the results from actions taken now will be clear in global temperature trends within two decades.
“We already have the technology and the know-how to get the job done,” said Inger Andersen, executive director of UN Environment Programme, during the press conference. “Stopping climate change will still be complicated, and long-term emission cuts may largely rely on technologies, like carbon dioxide removal, that are still unproven at scale. In addition to technological advances, cutting emission in industries that are difficult to transform will involve many factors.”
But in the near term, there’s a clear path forward for the emission cuts needed to put the planet on the right track. There are some of the tasks with the lowest cost and highest potential to address climate change during this decade, such as developing wind and solar power, cutting methane (甲烷) emission from fossil-fuel production and waste, protecting natural ecosystems that trap carbon, and using energy efficiently in vehicles, homes, and industries.
1. What is the author’s attitude towards tackling climate change?| A．Positive. | B．Worried. | C．Skeptical. | D．Uncertain. |
| A．It’s impossible to achieve the climate goal. |
| B．He knows how to cut emission efficiently. |
| C．The pace of global warming is speeding up. |
| D．He is dissatisfied with current emission cuts. |
| A．Policy. | B．Market. | C．Funding. | D．Technology. |
| A．Emission cutting is urgent. |
| B．Climate change is unstoppable. |
| C．Global warming is becoming complicated. |
| D．Meeting climate goals needs cooperation. |
7 . A year ago, I started working out with a personal trainer and the results were obvious. The reflection in the mirror was fit and strong, with a narrow waist. This month I’ll be celebrating my 74th birthday, but I feel more like I’m about to turn 40. In fact, I’m in the best shape of my life. And I’m here to tell you that it’s never too late to make changes. If I can do it in my early 70s, then you can do it too.
I haven’t always felt so body confident. As a busy working mum I had the same hang-ups as so many other women. In my forties I fell into the trap of trying to do it all. I raised my daughter Laura, now 43, while working as a NHS clinical leader, which left me feeling stressed and exhausted. By 50 I’d reached breaking point. I ended up breaking down in the doctor’s surgery. And I was signed off work with stress-related depression.
I began to do a lot of soul searching. My burnout had set me on a completely different path. Around this time, my approach to my health was also shifting. So many women hit 50 thinking that’s it and they’re done, but for me it felt like a new beginning.
I enrolled in a gym and learned how to use the equipments. Over the next few years, I went to the gym roughly twice a week. Sometimes I didn’t want to go—but at the end of every session I always felt better.
I wrote and self-published a book called Journey to Chocolate about my seeking for a more balanced and satisfying life. I started eating “clean” with lots of fresh fruit and vegetables, avoiding processed food and not drinking alcohol from Monday to Thursday. The changes to my diet made me feel more energetic and alert. I slept better, and managing my weight was much easier.
1. Why does the author write this article?| A．To inspire. | B．To inform. | C．To discuss. | D．To show off. |
| A．Annoying. | B．Tiring. | C．Rewarding. | D．Amazing. |
| A．The meaning of life. | B．The way to keep clean. |
| C．The author’s pursuit. | D．The benefits of chocolate. |
| A．Keep Energetic at 74 | B．Hold on to Your Dream |
| C．Retire as Early as Possible | D．Make Use of Old Age |
| A．Sophie. | B．Peter. | C．James. |
| A．$100. | B．$130. | C．$140. |
1. What TV channel is Jimmy Kimmel Live! on?
| A．NBC. | B．TBS. | C．ABC. |
| A．After he hosted the Oscars. |
| B．After Donald Trump became president. |
| C．When he cried at his show for the first time. |
| A．An interview. | B．A musical performance. | C．A comedy performance. |
| A．He taught in a drama school. |
| B．He worked at a radio station. |
| C．He went to school in Los Angeles. |
