Holding a cell phone against your ear or storing it in your pocket may be dangerous to your health. This explains a warning that cell phone manufacturers include in the small print that is often ignored when a new phone is purchased. Apple, for example, doesn’t want iPhones to come closer to you than 1.5 centimeters; Research In Motion, BlackBerry’s manufacturer, recommends 2.5 centimeters.
If health issues arise from cell phone use, the possible effects are huge. Voice calls - Americans chat on cell phones 2.26 trillion(万亿)minutes annually - earn $109 billion for the wireless carriers.
Devra Davis, an expert who has worked for the University of Pittsburgh, has published a book about cell phone radiation, “Disconnect.” The book surveys scientific research and concludes the question is not settled.
Brain cancer is a concern that Ms. Davis examines. Over all, there has not been an increase in its incidence since cell phones arrived. But the average masks an increase in brain cancer in the 20-to-29 age group and a drop for the older population.
“Most cancers have multiple causes,” she says, but she points to laboratory research that suggests low-energy radiation could damage cells that could possibly lead to cancer.
Children are more vulnerable(易受伤的)to radiation than adults, Ms. Davis and other scientists point out. Radiation that penetrates only five centimeters into the brain of an adult will reach much deeper into the brains of children because their skulls are thinner and their brains contain more absorptive fluid(易吸收的液体). No studies have yet been completed on cell phone radiation and children, she says.
Henry Lai, a research professor in the bioengineering department at the University of Washington, began laboratory radiation studies in 1980 and found that rats exposed to radiation had damaged DNA in their brains.
Ms. Davis recommends using wired headsets or the phone’s speaker. Children should text rather than call, she said, and pregnant women should keep phones away from the abdomen(腹部).
1.According to Ms Davis, brain cancer increase ____.
A.among children B.among old people
C.in the twenties D.among pregnant women
2.Why do children easily be affected by radiation?
A.Because they haven’t grown up.
B.Because they are too young to protect themselves.
C.Because they use cell phones more often than adults.
D.Because their skulls are thinner and their brains are easily hurt.
3.What can we conclude from the last paragraph?
A.Pregnant women should keep cell phones away.
B.People should use cell phones in the correct way.
C.If you are a child, you’d better text than make phone calls.
D.When you use a cell phone, use a wired headset or the phone’s speaker.
4.What does the passage mainly talk about?
A.Be careful when using cell phones.
B.Don’t hold your cell phone against your ear.
C.Rats exposed to radiation have damaged DNA in their brains.
D.Low-energy radiation could damage cells that could lead to cancer.
Wherever she goes, Molly leaves her mark. Without saying a word, she speaks to people with her kind eyes. Even when she walks away, she leaves an impression.Molly's mark is a smile, stamped into the ground by the horseshoe at the bottom of her false leg.
A few years ago, Molly was badly attacked by a dog.The dog bit all four or Molly’s legs and left large cuts in her face. Molly's owner, Kate Harris, took her to an animal hospital.Doctors there were able to save Molly’s life, but soon one of her legs became very infected(感染).
At first, doctors thought Molly would have to be put to sleep.But Molly changed their minds. This pony, doctors noticed, shifted her weight, and rested her good leg from time to time. Doctors knew t hat Molly had amazing intelligence, and that she wanted to live.
Several doctors operated on Molly, and removed her infected leg. A false leg was made for her. The leg was a hollow cast with a pole at the bottom for balance. Doctors gave Molly a special horseshoe at the bottom of the leg. This horseshoe she had had a stamp of a smile face in it!
After the operation, Molly walked around on all four legs, as if nothing had ever happened to her! Now, with every step she takes, she stamps a smile in the dirt.But she leaves her m ark in other ways, too.
Kaye Harris took Molly to the false leg center. There were children there who, like Molly, had artificial arms or legs. They were amazed to see a pony with a false leg. Molly made them smile and gave them hope. Soon, Molly began to visit schools, nursing homes, army bases and hospitals. A book was even written about Molly!
1.Molly is the name of a__________.
A.dog B.horse C.parent D.child
2.Which of the following is true according to the text?
A.Molly can speak to people in kind words.
B.Kay Harris took Molly to a children’s hospital after the attack.
C.In the beginning, doctors had planned to end Molly’s life.
D.Molly sometimes leaves smiling marks on people’s faces.
3.What is unique about Molly?
A.Molly has a false leg with a horseshoe shaped like a smiling face.
B.Molly ran a race and won the first prize.
C.Molly often visits places such as schools and parks.
D.Molly has become a symbol of hope for people of all ages.
Squirrels often communicate with whistles, chirps and chucks, which sound like the word “chuck”. Whistles and chirps are like the sounds that many birds make.Now scientists have translated some of their squirrel-speak.
Hare, a professor of zoology at the University of Maniloha in Winnipeg, and his team managed to record squirrels' alarm calls.The researchers studied the sounds and then played them back to 60 wild squirrels, which the scientists approached individually with a video recorder to capture(抓拍)their reponses.Some squirrels lifted their heads up and became.Alert(警惕的).Creatures that were more frightened simply ran for their lives and dived into caves.
"In effect then, whistles that mix with chucks say 'there's an enemy of average threat that's here', and whistles without chucks say 'there's an enemy of seemingly average threat around here somewhere', while pure chirps say, 'I'm hiding here because there's an immediate danger.' " Hare told.Discovery News.
Hare and some other researchers believe such sounds arc part of an advanced language that develops just as all other communication systems.
Although squirrels risk their lives when they call out to warn others of threats, other squirrels might admire this behaviour, thus increasingly the caller’s social status, like humans who look up to heroes. Hare added that other animals, such as birds, probably understand at least some squirrel language, since they also may benefit from the alarm calls.
In fact, another Canadian study found that deep-voiced, black-capped chickadees have their own language too.According to certain research, there are a lot of tidings in chickadees' calls, such as directing fellows' activities, keeping in contact between mates, and raising alarms.
While chickadees and other birds are often welcomed into gardens by homeowners, squirrels are frequently viewed as pests(害兽). Hare wishes a greater understanding of the complex social lives and communication systems of squirrels will provide “hope that humans will gain a greater appreciation and stop doing harm to these animals”.
1.The text mainly talks about
A.the study on the language of squirrels
B.the comparison between squirrels and chickadees
C.the calling for the protection of squirrels
D.the ways for squirrels to escape from their enemies
2.If a squirrel is in a very dangerous situation, it would probably make ____.
A.whistles with chucks B.pure chirps
C.whistles without chucks D.repeated chucks
3.The underlined word “tidings” in pardgmph 6 probably means ____.
A.difficulties B.poises C.messages D.languages
4.What can be learned from this text?
A.Squirrels communicate with cach other as humans do.
B.Some squirrels understand the recorded alarm calls.
C.Other animals also well understand the language of squirrels.
D.Birds such as chickadees don’t have their own language.
Life in the twenty-first century will be very 50 . Many changes will take place, but 51 will the changes be.
The population is growing 52 . There will be many 53 in the world and most of them will live 54 than people in the twentieth century.
Computers will be much smaller and 55 and there will be at least one in every 56 . And 57 studies will be one of the important subjects in school then.
People will work 58 and they will have more free time for sports, watching TV and travelling. 59 will be much easier and cheaper. And many more people will go to 60 countries for holidays.
There will be changes in our 61 , too. Maybe no one will eat meat every day, instead, they eat more fruit and vegetables. Maybe people will be 62 . Work in the future will be different, too. 63 and hard work can be done by robots. Because of this, 64 will not have enough work to do .This will be a problem.
1. A.interesting B.hard C.different D.beautiful
2. A.why B.how C.when D.what
3. A.slowly B.fast C.quietly D.suddenly
4. A.people B.workers C.scientists D.doctors
5. A.long B.longer C.happy D.lucky
6. A.more useful B.useful C.helpful D.less useful
7. A.hospital B.factory C.home D.town
8. A.science B.maths C.English D.computer
9. A.fewer hours B.more hours
C.eight hours D.more than eight hours
10. A.Seeing doctors B.Going to the cinema
C.Shopping D.Travelling
11. A.rich B.other C.poor D.small
12. A.food B.clothes C.fruit D.drinks
13. A.fatter B.thinner C.healthier D.more pleased
14. A.Safe B.Easy C.Simple D.Dangerous
15. A.a few people B.all the people C.many people D.some people
A .drive B. absolutely C. construct D. leadership E. Policies
F.realization G. Pressures H.Definition I.Challenging J. particularly
Leadership is a difficult concept to explain because everyone defines it differently. From my personal experiences as a student leader, I can tell you that there is no single ___1.___of leadership, ___2.___with students leaders. You are a leader, a student and a peer, so this role can be especially difficult to manage. As a student leader,you deal with academic__3.___,as well as added pressure of leading group of your peers. As, the president of Fuse, the contemporary dance group at Colgate University, I experienced many ups-and-downs with___4.__. Thankfully, my passion for this dance club gave me the ____5.___to lead my fellow dancers.
Finding an activity that is both enjoyable and __6.___is the first step. In order to be a good leader, you must be personally interested in what you are leading, whether it's debating,cooking or robotics. In my case, dance has always been of interest to me, from my grandfather teaching me salsa to early childhood training with ballet, and so I always that dance would be part of my life. Once I arrive on my college campus, ready for my college adventure, I had a sudden ___7.___: wandering around the Student Activities Fair, I saw no contemporary or modern dance clubs I panicked.
After meeting a fellow dancer at Freshmen Orientation, we found that we shared the same passion and desire to start a club. We held auditions,created club____8.___and held practices. The process of creating the actual club was both fun and challenging because we had to figure out school club regulations, __9.__many club rules, obtain 60 signatures of supporters and overcome other obstacles. As it turns out, this process was not a walk in the park for us.
I shall never forget those years _______ I lived in the country with the farmers, ______ has a great effect on my life.
A.that; which B.when; which
C.which; that D.when; who