An atom of ordinary carbon has six protons and eight neutrons

试卷相关题目

• 1The radiocarbon dating technique is only about 40 years old

  A.Right

  B.Wrong

  C.Not mentioned

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• 2Nowadays many scientists depend on radiocarbon for dating age-old objects

  A.Right

  B.Wrong

  C.Not mentioned

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• 3Ten years after the event， her death still remains a __puzzle__

  A.mist

  B.fog

  C.mystery

  D.secret

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• 4Many economists have given in to the fatal __lure__ of mathematics.

  A.attraction

  B.simplicity

  C.power

  D.rigor

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• 5These paintings are considered by many to be __authentic__.

  A.faithful

  B.royal

  C.genuine

  D.sincere

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• 6Radar is used to determine the characteristics of radiocarbon

  A.Right

  B.Wrong

  C.Not mentioned

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• 7Radiocarbon is reliable in dating an object back to at least 50，000 years.

  A.Right

  B.Wrong

  C.Not mentioned

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• 8The C-14 in an organism begins to decay when it dies

  A.Right

  B.Wrong

  C.Not mentioned

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• 9The half-life of C-14 is about 25，000 years.

  A.Right

  B.Wrong

  C.Not mentioned

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• 10Liquid water only exists

  A.in the center of the earth.

  B.on the surface of our planet.

  C.in a very narrow range of temperatures.

  D.in the coastal areas of the earth.

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