HUGEdu®新TOEFL模拟考试

6. Which of the following can be inferred from paragraph 4 about the radiometric dating of meteorites?

  • Scientists tried several different radiometric systems before finding one that worked.
  • The radiometric dating of different meteorites produced similar results.
  • Many meteorites were damaged by the radiometric dating.
  • Radiometric dating was not as accurate as scientists expected.

Paragraph 4

Meteorites have been radiometrically dated by means of several decay systems, including rubidium-strontium, potassium-argon, and uranium-thorium. The dates thus derived tend to cluster around 4.6 billion years, which suggests that this is the approximate age of the solar system. After many meteorites had been dated, it was gratifying to find that the oldest ages obtained for rocks gathered on the surface of the Moon also were approximately 4.6 billion years. This must, indeed, be the age of the solar system. Ancient rocks can be found on the Moon because the lunar surface, unlike that of Earth, has no water to weather and erode rocks and is characterized by only weak movements of its crust.

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