子机构
400-600-1123
logo GMAT备考资讯 答疑社区 GMAT公开课 提分课程
登录
注册

我的备考方案

获取方案

题库解析   >   观点对比型题型   >   RC33-35篇
    本题由lindy提供
3462次学习
RC33-35篇

Since the 1850s researchers have tried to show that variations in seasonal weather are connected in some ways with sunspots

, the outward sign of an increase in the Sun's activity. However, sciences lacked evidence supporting such a link until the mid-1980s, when van Loon and Labitzke compiled statistical evidence suggesting that a link exists and that it involves winds in the upper atmosphere above the equator which reverse their direction from east to west or west to east, every twelve to fifteen months. This phenomenon is called the quasi-biennial oscillation (QBO), and although meteorologists have known about the QBO since the 1950s, until the 1980s no one recognized a subtle but statistically significant link between the QBO and certain pattern of weather. When the west to east direction of winds in the upper atmosphere coincides with periods of high solar activity that occur approximately every eleven years, winters in the eastern and central United States are very cold.

On this basis, some meteorologists predicted that the winter of 1988-1989 in the United States would be severe. However, the winter was a mild one overall, and the meteorologists' attempt to make the connection between the Sun and weather on the Earth appeared unsuccessful, until Barston and Liverzey proposed a hypothesis explaining why the prediction had failed. They argued that the prediction had not taken into account another important element in the climate: the more or less regular pattern of fluctuations in the temperature of the surface waters of the tropical Pacific Ocean.

Barston and Livezey noted that when the water temperature is abnormally high-the phenomenon called EL Nino—the changes of cold winter weather over North American increase. The opposite situation, when surface temperatures are well below normal—La Nina—is far less common. In fact, until late 1988 no one had seen the combination of La Nina, westerly winds in the upper atmosphere, and high solar activity.

Thus, according to Barston and Livezey, La Nina cancelled out the effect of the other two climatic factors and caused the mild winter of 1988-1989. Although this hypothesis is plausible, much research remains to be done before meteorologists can establish and explain the effects of increased solar activity on seasonal weather changes.

The author of the passage would most likely agree

with which of the following statements about the link between increased solar activity and certain seasonal weather changes on the Earth?


    A.Because the evidence supporting such a link is questionable, future research in this particular area does not looking promising.
    B. Because it is unlikely that such a link can be definitely established, scientists should concentrate their efforts on investigating the role La Nina and other climatic factors play in influencing global weather patterns.
    C. Although some circumstantial evidence suggests that such a link exists, it is unlikely that future research will be able to confirm the existence of this link.
    D. There is evidence supporting the existence of such a link, but without further scientific investigation that evidence cannot be considered proof that such a link exists.

    E.Since the evidence clearly supports the existence of such a link, further research should focus on determining the implications of this link for the accurate prediction of changes in global weather patterns. 


登录申友留学,查看答案及解析
答案:
D
定位最后一
段Although this hypothesis is plausible,... increased solar activity on seasonal weather changes.虽然这里理论看起来可信,但是还需要further study去证实 选项A does not looking promising.错误 选项 B it is unlikely that such a link can be definitely established与文章内容不符,还有有意义的 选项C it is unlikely that future research will be able to confirm 可不可以被证实不知道,错误 选项D 正确 选项E Since the evidence clearly supports the existence of such a link, further research should focus on determining the implications与文章内容不符

参与讨论

提交
热门题目
申友gmat小助手

添加官方小助手微信
了解更多GMAT考试与咨询

吉祥物小蜜蜂
联系申友 全国免费咨询热线:400-600-1123

友情链接: 申友雅思 | 申友留学 | 申友GMAT官方微博 | 申友GMAT官方知乎机构账号

Copyright © 2020 All Right Reserved 申友教育 版权所有 沪ICP备17005516号-4 免责声明