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.

McFadden decided to find out whether people leave their DNA on their cell phones when she ____ .

       A. got her cell phone lost by chance        

       B. found a cell phone with blood on it

       C. heard about a crime involving a cell phone 

       D. did research on cell phones

The scientists allowed the volunteers to keep their cell phones for a week in order to____.

      A. let them leave their traces on their phones 

              B. avoid keeping their cell phones too long

              C. give them a chance to get rid of their secrets

              D. find out who is responsible for the crime

The last paragraph mainly tells us that cell phones ____ .

              A. do harm to people  B. should be often cleaned

              C. disclose people’s secrets       D. help deal with crimes

Which of the following is NOT mentioned in the passage?

              A. The reason for collecting the phones from volunteers.

      B. The technique of collecting DNA on the phones.

      C. The method of removing traces of DNA on the phones.

      D. The purpose of washing the cell phones.

第三节 完形填空(共20小题;每小题1.5分,满分30分)

阅读下面短文,从短文后所给各题的四个选项(A、B、C和D)中,选出可以填入

空白处的最佳选项,并在答题卡上将该项涂黑。

Nick was not the kind of boy I had expected to spend my summer with. I was hoping to     have a   21   the summer before my busy senior year, but my mother asked me to do her a   22  . One of her colleagues needed a full-time   23  . “You planned to volunteer at the local hospital, why not volunteer to   24   Nick instead?” Then she told me that this six-year-old boy was not a   25   child.

Nick was a lovely little boy who suffered from many disorders. Normal day-care centres would not   26   him. As a baby, he had serious ear infections which left him with equilibrium (平衡) problems. He couldn’t   27   or run properly. I was hesitating (犹豫)   28   I was to take the job when my mother   29  , “Don’t you want to be a nurse in the future? I doubt if you even have the   30  .”

Then I told her I was   31   for the job.

The day started at 7:00 a.m. Nick was my wake-up call! With so much energy and very little   32  , he was quite a mix.

At the park, when he saw all the other children play on the jungle gym and swings (秋千), the boy’s face   33   up — How he wished he belonged to the group of his age! You would think it would be   34   to get a child to go down a slide (滑梯). Believe me, it wasn’t! It took time, a lot of time. But with patience and support, Nick took one step up the slide each day. We worked together to face his   35   and gradually he got closer to taking the slide of his life.

Halfway through the summer, he   36   it to the top of the slide. With my arms   37   him tightly, we flew down the slide! I waited for his reaction. After realizing that he was safe and sound, he gave me a big   38   and asked, “May I go down again, alone?”

    I had never been happier in my life when I saw this little child climb the ladder and enjoy what other children   39   for granted.

    This   40   child taught me that being a nurse means respect, kindness and patience.

21. A. grade         B. course C. project                       D. relaxation

22. A. service                B. favour               C. business           D. trade

23. A. nurse        B. waitress           C. guard                                   D. guide

24. A. protect               B. defend              C. attend                                 D. comfort

25. A. normal                B. naughty            C. clever                                  D. happy

26. A. admit        B. receive             C. accept                                 D. adopt

27. A. speak        B. play          C. stand                                   D. walk

28. A. if                  B. what           C. why                             D. where

29. A. suggested          B. argued              C. challenged                D. commented

30. A. energy                B. courage            C. faith                            D. time

31. A. eager        B. sorry                 C. grateful            D. ready

32. A. awareness        B. balance            C. knowledge                D. control

33. A. delighted            B. cheered            C. lit                                 D. shut

34. A. difficult               B. simple               C. interesting                D. terrible

35. A. fears          B. worries             C. chances            D. situations

36. A. climbed               B. got           C. managed        D. made

37. A. taking                  B. holding             C. bringing            D. greeting

38. A. kiss             B. clap          C. welcome          D. surprise

39. A. play            B. do             C. take                            D. enjoy

40. A. miserable           B. smart                C. brave                                   D. special

It is the season…for long lines and frayed (紧张的) nerves. Here’s how to deal.

Lighten up

Do youreslf 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.

68.Airlines have reduced flights to___      .

  A. deal with crisis                    B. reduce the time for leave

  C.lower the cost                     D. provide more job chances

69. We can learn from the passage that____      .

  A. taking a taxi at the airport is expensive

  B. taxis stay at the airport free of charge

  C. cars can park at the airport for free

  D. JFK encourages people to take a taxi

70. What’s the best title for the passage?

  A. 5 Ways to Survey a Holiday Flight.      B. Good Seasons for Flight

  C. Cars at the Airport                    D. How to Board a Flight

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