题目内容

Your cellphone 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 victims.

Meghan J. McFadden, a biologist at McMaster University in Hamilton, Ontario, heard about a crime in which the suspect bled onto a cellphone and later dropped it. This made her wonder whether traces of DNA remained on cellphones - 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 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 they returned the phones and the researchers collected traces on each phone once more. They discovered DNA that belonged to the phone’s owner on each of the phones.

Surprisingly, DNA was even picked up immediately after the phones were cleaned. That suggests that washing won’t remove all traces of evidence from a criminal’s cellphone. So cellphones can be added to the list of clues that can settle a crime-scene investigation.

64. In a crime-scene investigation, now experts are likely to turn to ________.

A. the criminal’s fingerprint             B. the DNA analysis of physical items

C. the detectives                      D. the criminal’s cellphone

65. According to the passage, McFadden was inspired by ________.

A. the secrets stored in people’s cellphones   B. the special characters of DNA

C. a cellphone-involved case             D. the challenging job of detectives

66. According to the passage, the potential application of the new study would be ________.

A. identifying criminals         B. designing new cellphones

C. protecting individual privacy    D. preventing cellphone-involved crimes

67. Which of the following has the closest meaning with the underlined word “identify” in Paragraph 2?

A. imagine       B. recognize         C. discover          D. determine

 

【答案】

 

64.B 65.C 66.A 67.B

【解析】略

 

练习册系列答案
相关题目

A concert violinist was performing a difficult piece in front of a large audience. Suddenly there is a loud snap( 断裂声 ) and the__31___could be heard throughout the auditorium( 礼堂 ).The audience ___32___knew that a string( 弦)had broken. They all __33____the concert to stop for a short time ___34___another instrument was brought to the musician.

But instead, the __35___composed( 使镇定 ) herself and then signaled the conductor to start again.The orchestra( 管弦乐团 ) continued where they had __36___and the musician played the music on three strings. In her __37____she worked out new fingering to make up for the missing string. A work that few people could play __38___on four strings, the violinist played on three.

When she __39____and bowed to the audience,there was a silence in the hall. And then the crowd rose to their feet and cheered wildly. The violinist ___40___and wiped sweat from her forehead. When __41____returned to the hall, she ___42___why she had continued to play although there was a __43___string. "You know," she said, "sometimes it is the artist's __44___to find out how much music you can still ___45___with what has been left."

Maybe we've lived most of our lives and we have only a little time left. Maybe disease has ___46___us of our capacity( 能力 ) to work. Or perhaps a financial(财政的) loss has left us very__47___. Can we still make "music"?

There will come a time when we all __48___loss. Can we find the __49___to discover how much "music" we can still make with what has been left, just like the violinist? And if it takes extra courage to make the "music", others will __50___ your effort. Some people have lost more than others, but they are brave enough to face it. They inspire the rest of us to reach greater heights.

31. A. voice           B. sound         C.music        D. screamw

32. A.immediately      B. gradually       C. hardly       D.eventually

33. A. hoped          B. advised         C.urged        D.expected

34. A.when           B.until            C.after         D. since

35. A.audience        B.conductor        C.violinist      D.pianist

36. A.left             B. stopped         C.remained     D.arrived

37. A.hands           B. eyes            C.opinion      D.mind

38. A.fast             B.badly           C.well         D.gently

39. A.started          B.performed        C.finished      D.paused

40. A.worried         B.smiled          C.apologized    D.escapedw

41. A.thought         B.happiness        C.excitement    D.silence

42. A.asked          B. wondered        C.explained     D.introduced

43. A.broken         B.lost              C.bad          D.difficult

44. A.dream         B. plan              C. suggestion    D. task

45. A.take           B.get               C.make         D.carry

46. A.warned        B.reminded          C. required      D.robbed

47. A.poor          B.brave              C.guilty        D.rich

48. A.appreciate      B.avoid             C.experience     D.improve

49. A. assistance     B. hope              C. support       D.courage

50. A. comment      B.applaud            C. accept        D.blame

Help or Not

Dear editor,

During last year's winter holiday, I went shopping with my grandmother. We saw several beggars. Some of them were disabled, which made me feel sad. Among them were old people, young people and even children! When I wanted to help them, my grandmother stopped me. She told me they were not worth showing mercy to because some beggars cheated people out of their money. Should I help them?

                                                                                           Yours,

                                                                                           Mary from Guangzhou

Dear Mary,

       While I understand your grandmother’s point of view, I think that just because some beggars have cheated people, this doesn’t mean you should never help any beggars.

       Showing mercy to people who are not as fortunate as us is one of the kindest things we can do. While some beggars may use dishonest means to get money, most beggars will not. Even those who use dishonest means are probably hungry for food and feel they have no choice but to cheat people. It is important to be careful for your own safety. But if you want to help, you don’t necessarily have to give it to beggars in the street.

       Another way you can help is by donating money to the China Charity Federation. Visit its website at: www. china charity. cn.net.

18.From the grandmother’s point of view, we can learn that ________.

A. she has never helped the beggars.    

B. she believes not all beggars are honest

C. she has surely been cheated by some beggars  

D. she shows no pity for the poor

19. Mary felt sad for _______.

       A. her grandmother                                                 B. the disabled beggars 

C. the old people                                              D. herself

20. The editor suggests that Mary should _______.

       A. have her own mind                                      B. follow her grandmother

       C. do something for those unfortunate                D. help the China Charity Federation

21. The underlined word “donating” probably means _______.

       A. give out of kindness                                     B. put into a business

C. earn through an organization                         D. give in return for some kindness

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网