[讨论]xdf新东方阅读补充133页第89篇(90/10 Section 1A)第21题不懂，请指教。

vani

我用的是新东方比较新的一本白皮阅读补充材料。

这是一篇关于solar activity cycle的文章。

第21题，题目如下：

It can be inferred from the passage that the argument in favor of the model described in lines 37-45 would be strengthened if which of the following were found to be true?

A. Episodes of intense volcanic eruptions in the distant past occured in cycles having very long periodicities.

B. At the present time the global level of thunder-storm activity increases and decreases in cycles with periodicities of approximately 11 years.

C. In the distant past cyclical climatic changes had periodicities of longer than 200 years

D. In the last century the length of the sunspot cycle has been known to vary by as much as 2 years from its average periodicityof 11 years.

E. Hundreds of millions of years ago, solar-activity cycles displayed the same periodicities as do present-day solar-activity cycles.

文中37-45行是这样的：

Currently, there are two models of solar activity. The first supposes that the Sun's internal motions (caused by rotation and convection) interact with its large-scale magnetic field to produce a dynamo, a device in which mechanical energy is converted into the energy of a magnetic filed to produce a dynamo, a device in which  mechanical energy is converted into the energy of a magnetic field. In short, the Sun's large-scale magnetic field is taken to be self-sustaining. So that the solar-activity cycle it drives would be maintained with little overall change for perhaps billions of years. The alternative...

个人觉得，因我highlight的那句话，应该选E，但是答案是D，百思不得其解，盼指教。

谢谢！

vani

我有搜过了，好像没有。

因为xdf的材料现在好像题号不一样，所以搜起来不是很方便。

而且这一题说，inferred from line 37-45,我也贴了啊！我是诚心请教的。

vani

我问过在新东方上学的同学，说答案没错。所以我才特别疑惑。

谢谢楼上的同学：）