【推荐1】A study found wireless signals are able to pass through bags and suitcases to judge the sizes of dangerous metal objects and identify them. “These items could include weapons, chemicals, laptops and batteries for bombs,” the research team said on Tuesday.

Research suggested that Wi-Fi can now be used to estimate the volume of liquids such as water, acid, alcohol and other chemicals for explosive material. The study led by researchers at the Wireless Information Network Laboratory (WINLAB) in the School of Engineering showed a wireless device with two to three antennas (天线) that could be fitted in existing Wi-Fi networks.

The detection system analyzes what happens when wireless signals go through and bounce off objects or materials. The approach, which the paper states, works by separating the wireless interference (干扰) caused by two factors of objects — the material and shape. “Most dangerous objects such as weapons are usually metal or liquid, which have significant interference,” researchers said.

When it was tested on a backpack, the accuracy rate topped 95 percent. “But the accuracy dropped to about 90 percent when objects inside bags are wrapped. And the tech could save lives if used in museums, stadiums, theme parks or schools,” the team said, noting its design can inspect bags or luggage without being an exposure to privacy.

It uses channel state information (CS) that is readily available in low-cost Wi-Fi devices. “This could have a great impact on protecting the public from dangerous objects,” said Yingying Chen, a co-author of the study, “There’s a growing need for that now. In large public areas, it’s hard to set up expensive screening equipment like what’s in airports. Manpower is always needed to check bags and we want to develop a method to try to reduce manpower. “

The peer-reviewed study, which recently won a best paper award at the 2018 IEEE Conference on Communications and Network Security, is now published online. “Future work will continue to focus on improving the accuracy of identifying objects and imaging shapes and volumes,” researchers said.

1. What does paragraph 3 talk about?

A．The function of the technique.	B．The way the device works.
C．The principle the study is based on.	D．The benefit of the study findings.

2. What’s the advantage of the device?

A．It saves people in danger of natural disasters.

B．It passes through bags without damaging them.

C．It uses antennas to pick up networks’ signals.

D．It protects personal information from being exposed.

3. What is Yingying Chen’s attitude toward using the new device??

A．Indifferent.

B．Opposed.

C．Supportive.

D．Doubtful.

4. Which of the following is a suitable title for the text ?

A．Wireless Signals to Judge Metal Objects.

B．A Wireless Device for Identifying Danger.

C．Antennas to Be Fitted in Wi-Fi Networks.

D．Devices for Improving the Accuracy of Identifying Objects.

【推荐2】Who would have thought a teenager’s mobile phone could help them manage their mental health by supporting a good night’s sleep? A new app aimed at 12-to 16-year-olds is showing strong early results, improving both the hours of sleep and reducing depression and anxiety.

Sleep Ninja, a free app created by a mental health research organization — the Black Dog Institute, has shown significant early results in improving teenagers’ sleep patterns (模式), so critical not just for school readiness but for overall good mental health, co-creator Aliza Werner-Seidler said.

“Adolescents (青少年) struggle to get the recommended 8 to 10 hours of sleep each night,” Dr Werner-Seidler, a clinical psychologist, said. “As a result, approximately 40 per cent of all young people will experience a significant sleep problem by early high school which heightens their risk of mental ill-health, which is a risk factor for a range of disorders including depression and anxiety.”

Those using the app nominate a time to be up in the morning to make it to school or other activities. From there, it work backwards, determining when they should be in bed. The app gives an alert to start a pre-bed routine, which launches at least an hour before bed time. Part of that routine is to put the phone and other devices away, and engage in behaviors more suitable to sleep. Some of this is simply to have a shower, clean teeth, read a book. But the app also offers a form of practical tips to help them establish sleep routines, things like how to set up their bedroom, what to do during the day to improve their chances of sleep and how to reduce those negative repetitive thoughts that come in at night.

Dr Werner-Seidler said Sleep Ninja was the only such app designed specifically for adolescents, and the results so far had been very encouraging. She added that we also saw rates of depression drop from 77 percent at the start of the study to 44 percent after using the app.

1. What do we know about Sleep Ninja?

A．It aims to improve adults’ mental health.

B．It’s a new mobile phone for teenagers.

C．It is invented by 12-to 16-year-olds.

D．It’s a free app designed by Black Dog Institute.

2. What does the third paragraph focus on?

A．The creating process of Sleep Ninja.	B．The heavy burden of schooling.
C．The practical need for Sleep Ninja.	D．The cost of making Sleep Ninja.

3. How can Sleep Ninja work on teenagers?

A．By reducing negative repetitive thoughts.

B．By setting an alert in the morning.

C．By putting digital devices away.

D．By helping form good sleep routines.

4. In which section of a newspaper may this text appear?

A．Education Report.

B．Society Report.

C．Health Report.

D．Entertainment Report.

【推荐1】Delivery Robots May Soon Be Knocking at Your Door

With self-driving vehicle technology rapidly advancing, many companies are turning to autonomous robots for the final leg—the so-called last mile—of the delivery process, from the store or local distribution center to the customer. The latest to join the trend is Amazon. Following a successful eight-month test run in Snohomish County, Washington, the company’s Scout robots have been making the rounds of Irvine, California, since August 6, 2019.

The six-wheeled Scout is about the size of a large cooler with the ability to carry small or medium-sized packages. The battery-powered vehicle, which moves at a regular walking pace, has been programmed to avoid pedestrians, animals, and unexpected obstacles（障碍）, such as garbage cans. Its powerful sensors（传感器）can also detect the movement of a car backing out of a driveway.

While Amazon is focusing on home deliveries, San Francisco-based Starship Technologies has its eyes set on universities. On August 20, 2019, the company announced plans to use thousands of robots to deliver food and other things to students at college campuses across the country. Unlike Scout, Starship’s robots are seasoned workers. They have been tested in over 100 cities in 20 different countries and successfully completed over 100, 000 deliveries.

Meanwhile, food and grocery delivery company Postmates’ robots are currently making their rounds along the busy San Francisco streets. Also in testing, the robots can carry up to 50 pounds and travel 30 miles on a single battery charge.

Though the eco-friendly robots will help free our streets of bicycles and large delivery trucks that typically send packages, they have some limitations. They are unable to climb stairs or open gates, which means that they can only reach consumers who live on the ground level. Additionally, the robots are unable to leave packages at the front door if the customers are not home. Whether these problems get solved remains to be seen. For now, it appears that humans will still be needed to meet the ever-growing demand for home and office deliveries.

1. What does the underlined part in para l mean?

A．much more help	B．very close distance
C．substitute for human	D．the last section

2. We can learn from the passage that ________.

A．Powerful robots sensors are gaining popularity in delivery.

B．The Postmates’ robots focus on students' food and grocery delivery.

C．The Scout can avoid obstacles because it moves at a regular pace.

D．Delivery robots have turned up in universities to serve students.

3. What’s author’s attitude towards delivery robots？

A．Objective	B．Optimistic
C．Pessimistic	D．Cautious

4. From which is the text probably taken？

A．a biology textbook	B．a health magazine
C．a newspaper	D．a travel brochure

【推荐3】Discovery’s astronauts arrived to an exciting celebration Wednesday as nearly 700 people crowded an airplane storage place, waving flags and holding signs that read: “Welcome Home, Astronauts!”

The seven-person team returned to Earth on Tuesday after being the first to take a space shuttle into orbit since the Columbia disaster(灾难) of 2003.

“In the last two and a half years, we have been through the very worst that manned space flight can bring us, and over the past two weeks we have seen the very best,” NASA Administrator Michael Griffin told the astronauts and their families and fans Wednesday.

The crowd waved American flags for the U.S. astronauts and Japanese flags for crew member Soichi Noguchi, one of the spacewalkers.

“As a rookie（新手）astronaut, I could not ask for more,” Noguchi said, “We had three spacewalks, two extra days in space and one great team.”

While the homecoming has been filled with excitement for what mission controllers declared a “truly spectacular test flight”, uncertainty remains for the future of the shuttle program.

Shortly after Discovery rose up into space July 26, a nearly 1-pound large piece of foam insulation（泡沫绝缘材料） fell from the fuel tank—the very thing that was supposed to have been fixed after Columbia exploded. The foam missed Discovery, but NASA grounded all shuttle flights until engineers fix the problem.

NASA ground crews examined Discovery after its return from orbit and found it in good condition, an official said Wednesday at NASA’s Dryden Flight Research Center at Edwards Air Force Base in California.

Technicians counted 101 dings and divots, including 20 that were larger than 1 inch. Schaaf Dean, landing support group chief, said the numbers were similar to the results of other shuttle, post-landing examinations.

A beginning examination of the shuttle’s thermal（热的）blanket showed it remained undamaged during re-en-try into the Earth’s air.(Agencies)

1. The seven astronauts ________.

A．are the first to take a space shuttle into orbit

B．took the Columbia into space

C．returned to earth safely

D．are Americans

2. According to the text, the NASA officials think ________.

A．the flight of Discovery is a failure

B．manned space flight has been through the best in the past

C．the flight of Discovery is a success

D．the astronauts are national heroes

3. When the Discovery took off, ________.

A．the fuel tank burned	B．a piece of foam insulation fell
C．the safety belt is not fixed	D．it knocked into the Columbia

4. The underlined word “grounded” means ________.

A．(of a boat) hit the bottom of a sea and be unable to move

B．to cause a boat to hit the bottom of a sea or lake

C．to prevent a plane or person from flying

D．to be based on something

【推荐1】In the United States, many low income (低收入) parents cannot afford to buy enough food for their children. A program called Kids Café is helping some of these children by providing free nutritious (有营养的) snacks and meals during after-school programs.
At a community (社区) center in Virginia just outside of Washington, D.C., children make a snack as part of their afterschool program. “The snack is very healthy for your body, but the main thing is that it tastes really, really good,” Keith Clements tells them. He runs the Kids Café program.
The children are between the ages of 5 and 11 and are from several local schools. About half have parents from Ethiopia. Many of the children eat their traditional food at home. Kids Café, with food offered free by a food bank, gives them an opportunity to try different types of food.
“It’s good,” says one girl. But Rebecca Nance, whose parents are from the US, is not so sure. “The taste is weird.” Her mother, Daffany Nance has two children in the program. She’s glad her kids are getting nutritious food. “Even in my house we don’t have much junk food,” she says, “so it’s very important that it’s healthy and continues to help them grow better.”
The charity (慈善机构), Feeding America, started the national Kids Café program in 1993. The charity says more than 16 million children in the United States do not have enough healthy food to eat.
Kids Café became part of the afterschool program at this community center five years ago. Lori McFail heads the afterschool program. She says some children do not eat good evening meals because their parents work late or cannot afford healthy food. She hopes the children will make full use of what they’ve learned about nutrition in their lives.
1. What is the purpose of starting Kids Café?

A．To provide poor children with nutritious food.

B．To raise money for some poor children.

C．To develop the afterschool program.

D．To help poor children learn new skills.

2. The underlined word “weird” is the closest in meaning to _____.

A．delicious	B．unusual
C．terrible	D．strong

3. What can we learn about Daffany Nance?

A．She is from Ethiopia and has two children.

B．She cared little about her children’s diet before.

C．She believes the program is good for her children.

D．She hopes more types of food can be offered for free.

4. Who leads the afterschool program?

A．Lori McFail.

B．Keith Clements.

C．Feeding America.

D．A community center in Virginia.

【推荐2】[1] In 1856, a British survey team measured the height of Qomolangma with the result of 8,840 meters above sea level. However, the exact measurement has never been settled. In 1955, the figure was adjusted by an Indian survey team to 8,848 meters, and later to 8,850 meters according to a US team in 1999. And in 2005, a Chinese team gained a height of 8,844 meters, but that result wasn't widely accepted either.

[2] On May 6, 2020, a 30-member Chinese survey team, equipped with the latest technology, including a Global Navigation Satellite System receiver and a radar to measure the mountain's snow cap, is determined to settle the dispute (争议).

[3] But measuring Qomolangma is no easy task. The average air temperature there is -29℃ and hurricane-like winds blow all the time. According to Li Guopeng, leader of the No.1 Geodetic Survey Team of China's Ministry of Natural Resources, despite advanced technologies we now have — the likes of robots and drones — it’s uncertain that they can operate smoothly under extreme conditions, which is why sending human experts to the peak is still necessary to ensure a precise reading.

[4] But ______

[5] The truth is that measuring the height of Qomolangma is much more than just getting that one particular number. Mount Qomolangma is the perfect window for observing crustal (地壳的) movements. Tiny changes to the peak's height can indicate whether the two plates, the Eurasian plate and the Indian plate, are heading toward or away from each other. The survey team will also get firsthand information about the condition of the snow and other natural materials at the top, which could be an indicator of climate change on the Tibet-Qinghai Plateau.

[6] It might be true that settling a dispute was the driving force for continued exploration, but the good thing is that we always end up discovering so much more.

1. What is Paragraph 1 mainly about?

A．The importance of Qomolangma.	B．The dispute of Qomolangma’s height.
C．The difficulty in measuring Qomolangma.	D．The change of Qomolangma’s height.

2. What does Li Guopeng think of the new devices they carried?

A．They can read and deal with the results precisely.

B．They might break down under unusual conditions.

C．They are the latest advanced technology in the world.

D．They will work properly without human’s instructions.

3. Which of the following is best for the blank in the text?

A．what is the process of China’s measurement?

B．how is the latest technology used for the research?

C．does a tiny difference really matter for a huge mountain?

D．do extreme conditions actually affect the measurement?

4. What is to be discovered through the exact height of Qomolangma?

A．The depth of snowcap.	B．The diversity of natural materials.
C．The state of crustal movements.	D．The change of worldwide climate.

5. What is the writer’s purpose in writing the text?

A．To recommend a good way to settle a dispute.

B．To show the history of measuring Qomolangma.

C．To advertise China’s latest advanced technology.

D．To stress the value of China’s latest exploration in Qomolangma.