中间图

Or

雷哥网GMAT>题库>OG16>阅读RC>9385

阅读RC-9385 (第5/6题) Time Cost00:00
收藏
报告题目错误
请选择错误类型:
请描述一下这个错误:

取消

建议使用官方纸质指南,查看对照完整题目

Milankovitch proposed in the early twentieth century that the ice ages were caused by variations in the Earth’s orbit around the Sun. For some time this theory was considered untestable, largely because there was no sufficiently precise chronology of the ice ages with which the orbital variations could be matched.

To establish such a chronology it is necessary to determine the relative amounts of land ice that existed at various times in the Earth’s past. A recent discovery makes such a determination possible: relative land-ice volume for a given period can be deduced from the ratio of two oxygen isotopes, 16 and 18, found in ocean sediments. Almost all the oxygen in water is oxygen 16, but a few molecules out of every thousand incorporate the heavier isotope 18. When an ice age begins, the continental ice sheets grow, steadily reducing the amount of water evaporated from the ocean that will eventually return to it. Because heavier isotopes tend to be left behind when water evaporates from the ocean surfaces, the remaining ocean water becomes progressively enriched in oxygen 18. The degree of enrichment can be determined by analyzing ocean sediments of the period, because these sediments are composed of calcium carbonate shells of marine organisms, shells that were constructed with oxygen atoms drawn from the surrounding ocean. The higher the ratio of oxygen 18 to oxygen 16 in a sedimentary specimen, the more land ice there was when the sediment was laid down.

As an indicator of shifts in the Earth’s climate, the isotope record has two advantages. First, it is a global record: there is remarkably little variation in isotope ratios in sedimentary specimens taken from different continental locations. Second, it is a more continuous record than that taken from rocks on land. Because of these advantages, sedimentary evidence can be dated with sufficient accuracy by radiometric methods to establish a precise chronology of the ice ages. The dated isotope record shows that the fluctuations in global ice volume over the past several hundred thousand years have a pattern: an ice age occurs roughly once every 100,000 years. These data have established a strong connection between variations in the Earth’s orbit and the periodicity of the ice ages.

However, it is important to note that other factors, such as volcanic particulates or variations in the amount of sunlight received by the Earth, could potentially have affected the climate. The advantage of the Milankovitch theory is that it is testable; changes in the Earth’s orbit can be calculated and dated by applying Newton’s laws of gravity to progressively earlier configurations of the bodies in the solar system. Yet the lack of information about other possible factors affecting global climate does not make them unimportant.

【OG19-P3401-482题】

It can be inferred from the passage that precipitation formed from evaporated ocean water has

  • 分析A选项
    xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  • 分析B选项
    xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  • 分析C选项
    xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  • 分析D选项
    xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  • 分析E选项
    xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

音频解析

00:00/00:00

300雷豆
暂无雷哥网文字解析
当前版本由 ya**** 更新于2015-11-04 12:04:31 感谢由 ya**** 对此题目的解答所做出的贡献。
文中第二段(第19行)所在的句子谈到了蒸发的海水。根据后一句... the remaining ocean water... enriched in oxygen 18可以推测降水所含有的氧18比余下的海水中的含量要少
A错误,the same不对
B正确,符合文中意思
C错误,比较对象不对
D错误,precipitation formed from water on land不对
E错误,与氧16无关

题目讨论 (5条评论)

用户头像
提交
  • 用户头像
    showcjj

    这里ad说的是比例,bce直接用量比较,根本没有推算浓度。用排除法做才能稳健选出正确选项
    0 0 回复 2019-02-14 10:01:35
  • 用户头像
    Doriswpr

    定位次 evaporated ocean
    定位在 When an ice age begins, the continental ice sheets grow, steadily reducing the amount of water evaporated from the ocean that will eventually return to it. Because heavier isotopes tend to be left behind when water evaporates from the ocean surfaces, the remaining ocean water becomes progressively enriched in oxygen 18.
    肯定跟O 18 有关系 排除E 
    D定位错误 
    有比较 最后锁定BC 
    The remaining ocean water 可见是一种水和另一种水比较, 排除C
    2019-01-10 11:17:36
    0 0 回复 2019-01-10 11:18:12
  • 用户头像
    zhangxiao720

    evaporated ocean water 指的是 蒸发掉的海水。18很重,难以被蒸发上去。
    0 0 回复 2018-12-02 14:49:50
  • 用户头像
    jassicacanidy

    这里的precipitation是指的降水吧... 应该定位到steadily reducing the amount of water evaporated from the ocean that will eventually return to it. Because heavier isotopes tend to be left behind when water evaporates from the ocean surfaces, the remaining ocean water becomes progressively enriched in oxygen 18,既蒸发后的水会通过降水回到海里。重一点的同位素不会蒸发(会被留在海水里),因此剩下的海水中O18的浓度会非常高。因此降水中的O18浓度比海水中的低...
    1 0 回复 2018-11-27 13:47:16
  • 用户头像
    见过夏天去非洲拍动物世界

    Because heavier isotopes tend to be left behind when water evaporates from the ocean surfaces, the remaining ocean water becomes progressively enriched in oxygen 18.一定要对应原文,不要想当然,注意这里说的是一部分水蒸发, 另一部分水里18很多,注意说的是水,不是说冰!!!
    0 0 回复 2017-01-04 23:04:52
    题号选择

    科目: 阅读RC

    • 句子改错SC
    • 逻辑CR
    • 阅读RC
    • 数据充分DS
    • 问题求解PS
    • 综合推理IR

    来源: OG16

    • 全部
    • OG20
    • OG20新题
    • OG19新题
    • OG18新题
    • OG18分册
    • OG17新题
    • OG16
    • OG12
    • 破解版12
    • 破解版08
    • 破解版07
    • GWD
    • 精选题库
    • OG18自测章
    • Manhattan
    • magoosh
    • 难题300
    本题信息

    2m12s

    平均耗时

    61.9%

    平均正确率

    该题由网友t9AaA提供 上传GMAT题

    • 手机注册
    • 邮箱注册
    登录>







    关闭图标

    标题图

    • 图标

      知识库学习

      GMAT语法、逻辑、阅读、数学各单项备考知识点学习及测验
    • 图标

      在线做题

      包含GMAT各单项必考知识点题目、OG/PREP/GWD/雷哥讲义题目、难度650/680/700/730题库题目练习及题目解析
    • 图标

      在线模考

      语文套题/数学套题/全套仿真模考,包含GWD/PERP/精选模考等上百套套题模考
    • 图标

      在线测评

      适合5种不同基础的GMAT学员,测评后可自动出具分数报告及复习计划指导
    • 图标

      资料下载

      GMAT必备备考资料下载、鸡精下载、课程课件等免费下载
    • 图标

      课程学习

      注册会员后,可在GMAT课程区,选择免费直播课程及公开课程进行在线学习
    ×
    请你选择你要查看的模考成绩单
    立即开通 暂不开通
    加载图片
    网络异常