Scientists don’t know yet whether cell phones are bad for the brain.1.
In the experiment, the 47 participants may have looked a little strange. Each of them had two Samsung cell phones tied to his or her head—one on each ear.2. The phone on the right ear played a message for 50 minutes, but the participants couldn’t hear it because the sound was off. After 50 minutes with two phone attached to their heads, the participants were given PET scans. The PET scan is a way to take a three-dimensional picture of how the inside of the bodyworks.
The PET scan showed that the left side of each participant’s brain hadn’t changed from the way it was before the experiment.3. These right-side brain cells were using almost as much glucose as the brain uses when a person is talking. This suggests that brain cells there were active even without the person hearing or talking anything. This activity, the scientists say, was probably touched off by radiation from the phone.
4. They release different amounts of radiation depending on whether a person is talking or listening, the type of phone, the number of people using phones nearby, and the distance to the nearest cell phone tower. All of these changes make it difficult to collect evidence about any health risks of cell phones, since exposure to radiation can vary.
So for those who don’t want to wait to find out for sure whether cell phones are bad for the brain, there are ways to talk more safely.5.
A.The phone on the left ear was off.
B.So an experiment was done to attempt to find it out.
C.People should avoid having a long conversation by using cell phones.
D.Cell phones do not always give out the same amount of energy.
E.You can have short conversations, use a speakerphone to keep the phone away from your head.
F.The right side of the brain, however, had used more glucose, which provided fuel to brain cells.
G.From the PET scan the differences between the two sides of the brain were observed.
When Omar Yaghi was growing up in Jordan, his neighborhood received water for only about 5 hours once every 2 weeks. If Yaghi wasn’t up at dawn to turn on the taps to store water, his family, their cow, and their garden had to go without. At a meeting last week, Yaghi, now a chemist at the University of California, reported that he and his colleagues have created a solar-powered device that could provide water for millions in water-stressed regions. At its heart is a porous crystalline (多孔晶体) material, known as a metal-organic framework (MOF), which acts like a sponge: It sucks water vapor out of air, and then releases it as liquid water.
Yaghi and his colleagues first developed a zirconium( 锆 )-based MOF in 2014 that could harvest and release water. But at $160 per kilogram, zirconium is too expensive for massive use. So, last year, his team came up with an alternative called MOF-303, based on aluminum, which costs just $3 per kilogram, but the harvest was only about 0.2 liters per kilogram of MOF per day.
In July 2019, Yaghi reported that his team has designed a new and far more productive water harvester. Supported by a solar panel to power a fan and heater, which speed the cycles, the new device produces up to 1.3 liters of water per kilogram of MOF per day from desert air. Yaghi expects further improvements to increase that number to 8 to 10 liters per day. And his company plans to release a microwave-size device able to provide up to 8 liters per day this fall. The company promises an enlarged version next year that will produce 22,500 liters per day, enough to supply a small village.
However, it needs to be shown that Yaghi’s MOFs can be produced cheaply on a large scale. Each potential commercial MOF needs to prove itself in stability, efficiency, and life span. But if MOFs can pass those tests, they could offer a solution to some of the world’s most pressing problems.
1.Why is Omar Yaghi’s childhood mentioned at the beginning?
A.To show how serious water problem is. B.To lead in the topic.
C.To introduce the chemist. D.To arouse reader’s interest.
2.What is the problem of MOF-303?
A.It costs too much. B.It can’t last long.
C.It is hard to operate. D.It is low in efficiency.
3.According to Yaghi, how much water will a large water harvester produce per day?
A.1.3 liters. B.10 liters.
C.22,500 liters. D.8 liters.
4.What can be concluded from the last paragraph?
A.Yaghi’s MOFs are in great demand now.
B.Yaghi’s MOFs may help solve water shortage.
C.Yaghi’s MOFs have already entered the market.
D.Mass production of Yaghi’s MOFs is impossible.
On September 11, 2001, I was in the second week of the new school year with my senior English class at T. C. Williams High School just a few miles south of the Pentagon.
Suddenly that morning, a colleague who grew up in New York, opened the classroom door and said, "Turn on the TV the World Trade Center has just been hit by a plane. " I've always believed in never letting school get in the way of my students' education. I switched on the TV in front of the room, and my students and I listened to the announcers make a guess about what had happened——only to see the second plane hit. At first, the sight of the towers burning didn't seem to have much more immediacy (紧迫性)than a TV action movie. Soon, however, things in that classroom would get far too immediate.
In what seemed like about a half-hour after the second plane hit, we heard a loud explosion outside the school. Several students were shocked and I told them not to worry, saying that "it was just a car backfiring". A moment later a boy sitting near the windows said, "That's no car； look at that black smoke." We could see an enormous plume of smoke rising in the distance, but didn't know where it was coming from until, a few seconds later, the NBC reporter stationed at the Pentagon broke into the New York coverage to say that he felt the ground shake beneath him as he heard an explosion—obviously the same one that had just surprised my students. It was several minutes before it was announced that the explosion came from a plane hitting the Pentagon.
At that point, a boy a football player suddenly came undone and had to be comforted by the girls in the class. His mom worked in the Pentagon, and when he tried to get her on his cellphone he could not get through.
Reports vastly overestimated the number of deaths in the Pentagon. Some reports were estimating over 800 dead when the actual death toll at the Pentagon was 125.
1.The author was working as on September 11, 200____.
A.a security guard B.a teacher in a school
C.a TV reporter for NBC D.an officer in the Pentagon
2.What can be inferred from the second paragraph?
A.Another plane hit the Pentagon before the author turned on the TV.
B.The author thought the hit got in the way of his students' education.
C.The author's colleague forced him and his students to watch the TV report.
D.The author believed that there exists something deserving attention besides school.
3.Which of the following is TRUE based on the third paragraph?
A.The boy sitting near the windows witnessed the hit.
B.The author tried to comfort his students by telling them the truth.
C.The loud explosion was caused by the plane hitting the Pentagon.
D.The author realized the Pentagon was hit immediately he heard the loud explosion.
4.What does the author mean by mentioning the football player suddenly came undone?
A.The football player lost self-control as he was unable to contact his mum.
B.The football player felt at a loss as his mum left without saying good-bye.
C.The football player was terrified when a car crashed against the school gate.
D.The football player exploded with anger since he was forbidden to use his cell phone.
It was once common to regard Britain as a society with class distinction. Each class had unique characteristics.
In recent years, many writers have begun to speak the 'decline of class' and 'classless society' in Britain. And in modern day consumer society everyone is considered to be middle class.
But pronouncing the death of class is too early. A recent wide-ranging society of public opinion found 90 percent of people still placing themselves in particular class; 73 percent agreed that class was still a vital part of British society; and 52 percent thought there were still sharp class differences. Thus, class may not be culturally and politically obvious, yet it remains an important part of British society. Britain seems to have a love of stratification.
One unchanging aspect of a British person's class position is accent. The words a person speaks tell her or his class. A study of British accents during 1970s found that a voice sounding like a BBC newsreader was viewed as the most attractive voice. Most people said this accent sounded 'educated' and 'soft'. The accents placed at the bottom in this study, on the other hand, were regional city accents. These accents were seen as 'common' and 'ugly'. However, a similar study of British accents in the US turned these results upside down and placed some regional accents as the most attractive and BBC English as the least. This suggests that British attitudes towards accent have deep roots and are based on class prejudice.
In recent years, however, young upper middle-class people in London, have begun to adopt some regional accents, in order to hide their class origins. This is an indication of class becoming unnoticed. However, the 1995 pop song 'Common People' puts forward the view that though a middle-class person may 'want to live like common people' they can never appreciate the reality of a working-class life.
1.A recent study of public opinion shows that in modern Britain ________.
A. people regard themselves socially different
B. most people belong to middle class
C. it is easy to recognize a person’s class
D. it is time to end class distinction
2.The word “stratification” in Paragraph 3 is closest in meaning to ________.
A. variety B. qualification C. authority D. division
3.British attitudes towards accent ________.
A. are based on regional status
B. have a long tradition
C. are shared by the Americans
D. have changed in recent years
4.What is the main idea of the passage?
A. The middle class is expanding
B. A person’s accent reflects his class
C. Class is a key part of British society
D. Each class has unique characteristics.
It is the season for long lines and frayed nerves. Here’s how to deal.
Lighten up
Do yourself a favor and ship your presents. Nearly every U.S. airline charges a fee to check a bag, so shipping gifts is now cheaper and more convenient than carrying them in your luggage.
Weigh your options
Now knowing what you’re going to pay for your luggage is annoying. So calculate your overweight-luggage fees at home. You can find the fees out in advance by visiting new site Luggage Limits, which provides the latest information on more than 90 airlines.
Leave amateurs in the dust
Trust us and get to the airport an extra half-hour early. The check-in and security lines are filled with inexperienced fliers, and it’s a hard walking. Plus, if you decide to cut it close, you may not get onto the flight at all. To reduce costs, airlines have reduced on flights and routes. The remaining flights are more likely to be oversold, especially on busy travel days. Fliers who check in early are the least likely to get bumped from oversold flights.
Take it public
The rates for renting a car at the airport have more than doubled over the past year because rental lot inventories (财产) have increased dramatically. True, renting at the airport is convenient, but it’s just not worth it anymore. Unless you really need a car, take public transportation, hop a cab, or beg a friend to pick you up at the airport instead.
Say no to bumper cars
Tell the people picking you up to avoid parking their car. They can hang out in their car for free while waiting to get a call from you when you land. Many airports, including JFK and LAX, now feature this sensible choice.
1.Airlines have reduced flights to .
A.lower the cost B.deal with crisis
C.reduce the time for leave D.provide more job chances
2.We can learn from the passage that _____.
A.many airports like JFK provides free parking service
B.shipping presents is more expensive than carrying them in luggage
C.taking a cab at the airport is less expensive than renting a car
D.Luggage Limits can give a discount on overweight luggage fees
3.What’s the best title for the passage?
A.Cars at the Airport B.Good Seasons for Flight
C.How to Board a Flight D.5 Ways to Survive a Holiday Flight.
请阅读下面文字及图片，并按照要求用英语写一篇150词左右的文章。
So Close, Yet So Far
Where am I? What am I doing? If you’re one of my 500 friends online, you’ll always be the first to know. My phone and laptop are never out of touching distance, so I’m constantly posting updates on social media—whether I’m having a coffee, on my way to school, watching TV… even when I’m in the shower. I have a never-ending flow of messages and updates from all the people I associate with online.
I live in a university dorm with a couple of great roommates. Yet the truth of the matter is: I feel lonely. A few days ago, I went out for a dinner get-together with some friends. My best friend left the table for 30 minutes because he had to take a call. Some spent the dinner bent over their phones, texting friends online but ignoring the one who sat right in front of them. And the extraordinary thing is no one thought this was rude; it’s just how life is nowadays.
（写作内容）
1. 用约 30 个单词概述上述文字所描述的现象；
2. 分析造成该现象的原因（两至三点）；
3. 请你给 Mark 提两到三条建议。
（写作要求）
1. 写作过程中不能直接引用原文语句；
2. 作文中不能出现真实姓名和学校名称；
3. 不必写标题。
（评分标准）
内容完整，语言规范，语篇连贯，词数适当。
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