Question

Two scientists in California now think they can find out a person’s real age.Jeffery Bada and P..

Two scientists in California now think they can find out a person’s real age.Jeffery Bada and Patricia Masters do chemical tests on teeth.When we are born the amino acids（氨基酸）in our teeth are in one form.Then，as we grow older these amino acids change into a second form.Every year，one thousandth of the amino acids changed.So，by testing just one tooth and counting the number of amino acids in each form，Bada and Masters can work out a person’s age.They tested a tooth from the body of an Eskimo（爱斯基摩人）woman who died 1 600 years ago.From the appearance of her body，she was between 50 and 60 years old when she died.The tooth test put her age at 53.Then the Russian Government sent them a tooth from an old man in Georgia.The tooth said she was 99.Her real age was 96.The Russians are now hoping to send more teeth，from the very old people without birth certificates（出生证明书）.But there are problems.Some of the centenarians（百岁老人）have lost all their teeth.The others want to keep their teeth until they drop out naturally.So the Russian Government and the American scientists have to wait and hope.61.Jeffery Bada and Patricia Masters believe that they can tell a person’s age according to_______.A.an experiment on his boneB.the shape and condition of his teethC.a test on the amino acids within his bodyD.the changing form of amino acids in his teeth62.According to the passage，which of the following statements is true?A.The amino acids in an adult’s teeth may differ from those in a baby’s.B.The number of amino acids in a 20-year-old man is different from that when he was seven.C.Amino acids in one teeth changes without affecting their forms.D.Scientists no w can tell how long a person will live by testing his teeth.63.Why are the two scientists asked to find out some very old Russians’ age?A.Because the Government wants to know how long these old people can live.B.Because they have no birth certificates.C.Be cause people who have tooth problems tend to live longer.D.Because the Government wants to know their dates of birth and death.64.In order to find out the exact age of some people over 100，both the Russian Government and American scientists_______.A.should wait until all of them dieB.should pull out one of their teethC.have to wait for their teeth to drop out naturallyD.want to have their teeth pulled out65.The central idea of the passage is_______.A.the relationship between people’s teeth and agesB.the relationship between amino acids and teethC.the contradiction（矛盾）between scientists and patientsD.the contradiction between the Government and the scientists

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Answer 1

61-65 DABCA

61. 文章的第二句中可以找到答案。 62.文章第三句“Then,as we grow older these amino acids change into a second form.”可作为本题的答案依据。 63. “The Russians are hoping to send more teeth,from...”一句可作为本 题的依据。 64.有些老人不愿拨掉牙齿，科学家们只好等待。 65.中心概括题。