2. 外语
  3. Hitherto, there is no evidence yet that would definitively prove whether or not some dinosaurs were warm-blooded, but scient

Hitherto, there is no evidence yet that would definitively prove whether or not some dinosaurs were warm-blooded, but scient

admin2009-05-19  68
问题         Hitherto, there is no evidence yet that would definitively prove whether or
    not some dinosaurs were warm-blooded, but scientists have begun to investigate
    oxygen isotopic abundances in the annual growth bands of teeth or bones of high
    latitude, hence seasonally influenced, terrestrial dinosaurs. The ratio of oxygen
(5)  isotopes depends on temperature, and an absence of seasonal variations in
    oxygen 18—a heavy version of the common oxygen 16 atom—would strongly
    suggest that the animals maintained a constant internal temperatures. Such a
    finding would not, however, constitute "proof" that dinosaurs were warm
    blooded, as there are external mechanisms that cold-blooded animals employ to
(10) regulate body temperatures and thereby influence metabolic rates. More
    nettlesome is that proof would have to come from discovery of intact dinosaur
    remains in which the soft tissue had not been replaced or altered, and from
    which the biomolecules responsible for thermoregulation could be extracted
    identified and characterized. Such a proof is unlikely, as it would require an
(15) almost impossible level of preservation over 65 million years, plus the advent of
    biotechnology that does not yet exist.
选项 A、answer a theoretical question in the field of dinosaur thermoregulation
B、discuss the current state of research in the field of dinosaur thermoregulation
C、resolve a dispute in the field of dinosaur thermoregulation research
D、predict a future crisis in the field of dinosaur thermoregulation research
E、suggest some of the possible benefits of a technique in dinosaur thermoregulation research
答案B
解析
转载请注明原文地址:https://kaotiyun.com/show/17kO777K
本试题收录于： GRE VERBAL题库GRE分类
0

GRE VERBAL

GRE

相关试题推荐
随机试题
最新回复(0)