Your cell phone holds secrets about you. Besides the names and numbers that you’ve programmed into it, traces of your DNA remain on it, according to a new study.
DNA is genetic material that appears in every cell. Like your fingerprint, your DNA is unique to you --- unless you have an identical twin. Scientists today usually analyze DNA in blood, saliva(唾液), or hair left behind at the scene of a crime. The results often help detectives identify criminals and their victims.
Meghan J. McFadden, a biologist at McMaster University in Hamilton, Ontario, heard about a crime in which the suspect bled onto a cell phone and later dropped the device. This made her wonder whether traces of DNA remained on cell phones --- even when no blood was involved. To find out, she and a colleague collected flip-style(翻盖式) phones from 10 volunteers. They collected invisible traces of the users from two parts of the phone: the outside, where the user holds it, and the speaker, which is placed at the user’s ear.
The scientists scrubbed(meaning “cleaned”) the phones using a liquid mixture made mostly of alcohol. The aim of washing was to remove all detectable traces of DNA. The owners got their phones back for another week. Then the researchers collected the phones and repeated collecting traces on each phone once more. They discovered DNA that belonged to the phone’s owner on each of the phones.
Surprisingly, DNA showed up even in swabs that were taken immediately after the phones were cleaned. That suggests that washing won’t remove all traces of evidence from a criminal’s cell phone. So cell phones can now be added to the list of clues that can help a crime-scene investigation.
1.McFadden decided to find out whether people leave their DNA on their cell phones when she ____ .
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A．got her cell phone lost by chance |
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B．found a cell phone with blood on it |
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C．heard about a crime involving a cell phone |
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D．did research on cell phones |
2.The scientists allowed the volunteers to keep their cell phones for a week in order to____.
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A．let them leave their traces on their phones |
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B．avoid keeping their cell phones too long |
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C．give them a chance to get rid of their secrets |
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D．find out who is responsible for the crime |
3.The last paragraph mainly tells us that cell phones ____ .
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A．do harm to people |
B．should be often cleaned |
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C．disclose people’s secrets |
D．help deal with crimes |
4.Which of the following is NOT mentioned in the passage?
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A．The reason for collecting the phones from volunteers. |
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B．The technique of collecting DNA on the phones. |
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C．The method of removing traces of DNA on the phones. |
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D．The purpose of washing the cell phones. |
TOURNAMENT OF ROSES
-- 5 Days Los Angeles
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Day 1 Los Angeles. (Sun. , Dec. 30) Welcome to Los Angeles! This evening mix with your traveling companions at the welcome reception. Day 2 Los Angeles. (Mon. , Dec. 31) Head to Pasadena for the always colorful ROSE BOWL FAMILY FESTIVAL and watch the floats(彩车) decorated with tens of thousands of flowers. This afternoon, you can take the included visit to the GETTY MUSEUM. This evening , join your traveling companions at a special New Year’s Eve DINNER AND DANCE GALA(盛会), complete with hats, party favors, live music, and, of course, champagne! You’ll toast the New Year a little early tonight to allow for an early morning departure to the Rose Parade. Day 3 Los Angeles. Tournament of Roses Parade. (Tue. , Jan. 1) Happy New Year! Get ready for one of the world’s most popular parades, and you’ll see it live! Globus has booked the GRANDSTAND(在大看台上的) SEATS at the beginning of the parade route for a good view. See the wonderful floral(饰以花的) floats, marching bands from around the world, and the celebrities. Day 4 Los Angeles. (Wed. , Jan. 2 ) This morning view the individual floats in the POST PARADE VIEWING AREA. For many this is the highlight(最精彩的部分) of the entire event. Be sure to bring your camera and plenty of film! Another special treat tonight --- a special GOLBUS FAREWELL CELEBRATION DINNER. Day 5 Los Angeles. (Thu. , Jan. 3) The tour ends today, with tour guests departing on individual schedules. |
1.You can most probably read the passage in a ___ .
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A．news report |
B．travel guide |
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C．textbook |
D．history magazine |
2.What activity can visitors enjoy on Dec. 31?
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A．Tournament of Roses Parade. |
B．Post Parade. |
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C．A farewell celebration dinner. |
D．A dinner and dance gala. |
3.The underlined word “Globus” in the passage refers to “____”.
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A．the travel agency |
B．the local government |
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C．Los Angeles |
D．Roses Parade |
4.According to the passage, you should bring your camera on ____.
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A．Day 2 |
B．Day 3 |
C．Day 4 |
D．Day 5 |
Probably many of you know the idiom “an eye for an eye and a tooth for a tooth”. But do you believe a tooth for an eye? That’s something a little bit different.
This strange exchange is neither a form of retribution(报应) nor an unexpected gift from the Tooth Fairy --- it’s actually a very generous gift from a young Irishman, Robert McNichol, 23, to his formerly blind father, 57-year-old Bob McNichol.
In 2005, Bob McNichol’s sight was destroyed in an accident when his eyes were doused(溅在……上面)with liquid aluminum(铝). Doctors predicted that he would never be able to see again.
But McNichol never liked to take no for an answer: when he heard about a unique operation called Osteo-Odonto-Keratoprosthesis, he knew he had to give it a shot, even though the success rate was a mere 65 percent.
In the technique, the eye socket(眼窝) is rebuilt and implanted(植入) with a human tooth and part of the jawbone, to provide support for an artificial cornea(角膜). Luckily for McNichol, Robert was willing to sacrifice one of his teeth to help his father regain his sight.
The technique isn’t simple: McNichol’s first stint on the operating table lasted ten hours, with a five hour follow-up session at a later date. But thanks to his son’s gift, he’s already seeing astonishing results.
“Now I have enough sight for me to get around and I can watch television. I have come out from complete darkness.” he told his friends.
1.Bob McNichol lost his sight ____ .
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A．after he had an operation on his eyes |
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B．because of an accident |
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C．because he met with a serious traffic accident |
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D．when he was 57 years old |
2.The underlined phrase “give it a shot” (in Paragraph 4) probably means “____”.
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A．give it a try |
B．make a remark |
C．fire a gun |
D．kick the ball |
3.The tooth Bobert donated to his father is used to ____ .
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A．make the eye socket look prettier |
B．cause his jawbone to function well |
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C．help his father take in more food |
D．support the implanted artificial cornea |
4.What would be the best title for the passage?
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A．Father and son |
B．A unique eye operation |
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C．A man defeating darkness |
D．Blind man sees with aid of son’s tooth |
--Hi, is Mary there, please?
---
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A．Hold on, I will get her. |
B．Don’t mention her, please. |
|
C．Yes, she lives here. |
D．Yes, what do you want? |
I paid a visit to the small town last week where I was born, which I hadn’t
visited for years.
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A．Every time |
B．Once more |
C．On time |
D．Now and then |
after having been painting the house all day, James called, saying he
wouldn’t come to our party.
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A．Having tired out |
B．Being tired out |
C．To be tired out |
D．Tired out |
