1. In the passage, the author is primarily interested in主题题（写法性）
(A) suggesting an alternative to an outdated research method
(B) introducing a new research method that calls an accepted theory into question
(C) emphasizing the instability of data gathered from the application of a new scientific method
(D) presenting a theory and describing a new method to test that theory问题解决型，主题题不考虑延伸性内容（D）
(E) initiating a debate about a widely accepted theory
2. The author of the passage would be most likely to agree with which of the following statements about the Milankovitch theory?看似信息题，实为态度题
(A) It is the only possible explanation for the ice ages.
(B) It is too limited to provide a plausible explanation for the ice ages, despite recent research findings.
(C) It cannot be tested and confirmed until further research on volcanic activity is done.
(D) It is one plausible explanation, though not the only one, for the ice ages.正评价，但不是唯一可行的理论（D）
(E) It is not a plausible explanation for the ice ages, although it has opened up promising possibilities for future research.
3. It can be inferred from the passage that the isotope record*3 taken from ocean sediments would be less useful to researchers if which of the following were true?改善题的变体（重要题型）
(A) It indicated that lighter isotopes of oxygen predominated at certain times.
(B) It had far more gaps in its sequence than the record taken from rocks on land.找优点（时间连续性，地理连续性），取非
(C) It indicated that climate shifts did not occur every 100,000 years.
(D) It indicated that the ratios of oxygen 16 and oxygen 18 in ocean water were not consistent with those found in fresh water.（B）
(E) It stretched back for only a million years.
4. According to the passage, which of the following is true of the ratios of oxygen isotopes in ocean sediments*4?信息题（有定位，形同虚设，看第二段首次出现）
(A) They indicate that sediments found during an ice age contain more calcium carbonate than sediments formed at other times.
(B) They are less reliable than the evidence from rocks on land in determining the volume of land ice.
(C) They can be used to deduce the relative volume of land ice*4C that was present when the sediment was laid down.
(D) They are more unpredictable during an ice age than in other climatic conditions.（C）
(E) They can be used to determine atmospheric conditions at various times in the past.
5. It can be inferred from the passage that precipitation formed from evaporated ocean water has 浅层理解题
(A) the same isotopic ratio as ocean water
(B) less oxygen 18 than does ocean water因为O18比较重，不太能蒸发出来
(C) less oxygen 18 than has the ice contained in continental ice sheets
(D) a different isotopic composition than has precipitation formed from water on land（B）
(E) more oxygen 16 than has precipitation formed from fresh water
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