求助！牛牛！阅读大全76的二道题！！

jerryjay

Desertification, the creation of desert-like conditions where none had existed before, is the result of the vagaries of weather and climate or the mismanagement of the land or, in most cases, some combination of both. Such ecological deterioration in the Sahel (sahel: 荒漠草原(西非) ) has been linked in several ways to the increased size of livestock herds. During the fifteen years preceding 1968, a period of extremely favorable rainfall, the pastoralists (牧(羊)人)
moved into the marginal regions in the north with relatively large herds. However, with the onset of a series of dry years beginning at the end of the rainy season in 1967, the pastoral populations found themselves overtaxing very marginal rangelands, with the result that the nomads viewed themselves as victims of a natural disaster. The mistaken idea that drought is an unexpected event has often been used to excuse the fact that long-range planning has failed to take rainfall variability into account. People blame the climate for agricultural failures in semiarid regions and make it a scapegoat for faulty population and agricultural policies

Deterioration and ultimately desertification in the Sahel and in other ecosystems can be combated only if an ecologically realistic carrying capacity for the rangelands is determined. Although there appears to be widespread agreement that such a determination would be significant, there has been little agreement on how to make operational the concept of carrying capacity, defined as the amount of grazing stock that the pasture can support without deterioration of either the pasture or the stock. Should the carrying capacity (carrying capacity:承载能力) be geared to the best, the average, or the poorest years? Which combination of statistical measures would be most meaningful for the planning of long-term development of rangelands? On which variables should such an assessment be based, vegetation, rainfall, soil, ground and surface water, or managerial capabilities? Such inconclusiveness within the scientific community, while understandable, creates confusion for the land managers, who often decide to take no action or who decide that all scientific suggestions are of equal weight and, therefore, indiscriminately choose any one of those suggested. Given the downward spiral of land deterioration, it becomes essential that an ecologically acceptable carrying capacity be established and enforced.
It will also be crucial that land managers know what statistical and quasi-statistical measures actually mean: no single number can adequately describe the climate regime of an arid or semiarid region. Land managers must supplement such terms as the “mean” with more informative statistical measures to characterize adequately the variability of the climate. The understanding of this high degree of variability will serve to remove one of the major obstacles to resolving the perennial problems of the Sahel and of other arid or semiarid regions.


3. It can be inferred from the passage that the nomadic tribes who moved into the marginal regions of the Sahel did NOT
(A) enlarge the size of their livestock herds
(B) conserve water after the drought began
(C) live in the Sahel after 1968
(D) expect a drastic change in weather conditions
(E) seek governmental aid in overcoming drought conditions
答案选D，但是我感觉BDE原文都没提到啊。是我没找到吗？

4. It can be inferred from the passage that the concept of the carrying capacity of land is
(A) still hypothetical rather than practical
(B) basically political rather than ecological
(C) independent of climatic conditions
(D) relatively unknown among ecologists
(E) generally misrepresented by ecologists
答案是A。 但原文中提到了Given the downward spiral of land deterioration, it becomes essential that an ecologically acceptable carrying capacity be established and enforced.这不是说应该尽快建立一个 ecologically可接受的carrying capacity 吗？而且也提到了there appears to be widespread agreement that such a determination would be significant, there has been little agreement on how to make operational the concept of carrying capacity,这不算political吗？
希望牛牛现身指导！！！感谢！！！

jerryjay

第三题的补充。
The mistaken idea that drought is an unexpected event has often been used to excuse the fact that long-range planning has failed to take rainfall variability into account. 既然都不把降水量的变化考虑进计划里，那么久肯定不会存水了。
但是D选项，既然认为干旱是一个预料之外的事件，那么很自然的就应该期望天气的好转啊？
E选项感觉原文完全没提啊！

littlebluesks

不是NN.
第三道题我也错了。
关于第四道题我的看法是，第二段一开头说的是“Deterioration and ultimately desertification in the Sahel and in other ecosystems can be combated only if an ecologically realistic carrying capacity for the rangelands is determined.”，deterioration and desertification 的问题只有在an ecologically realistic carrying capacity for the rangelands被determined时能被解决。按照正常逻辑，应该是解说上一句中的an ecologically realistic carrying capacity for the rangelands怎么被determined，但是文章却接着说Although there appears to be widespread agreement that such a determination would be significant, there has been little agreement on how to make operational the concept of carrying capacity，也就是说虽然这种determination很重要，但是还是没有一个意见上的一致如何取得这种determination。接着文章用了几个问句“Should the carrying capacity (carrying capacity:承载能力) be geared to the best, the average, or the poorest years? Which combination of statistical measures would be most meaningful for the planning of long-term development of rangelands? On which variables should such an assessment be based, vegetation, rainfall, soil, ground and surface water, or managerial capabilities?”来说明取得意见的一致是很困难的。A选项说concept of the carrying capacity of land仍然是hypothetical rather than practical是有道理的，所以选它。
个人意见，希望能有帮助吧。

finnlijing

我来帮你顶，第三题我也错了；另，请问NN阅读怎么复习的，我复习一个月了，依然大全大部分文章错一半，完全没有感觉