passage 68 灰松鼠，跟竞争没关系

★★★

看题：

1. It can be inferred that the author of the passage mentions the efficiency with which gray squirrels forage primarily in order to 推断+信息目的

2. It can be inferred that the author of the passage would be most likely to agree with which of the following statements about the “early view“? 推断+作者态度

两题推断，难，更需要找准定位。

文章分析（方法来自武汉Sugar老师）：

①An influential early view held that ecosystems contain niches for a limited number of species and that competition for resources among species—whether native or nonnative invading ones—determines ecosystems' species composition. ②However, factors other than competition often help explain invading species' success. ③For example, the American grey squirrel, often cited as a classic example of competitively superior invading species, was introduced in England in 1876 and now thrives, while the native red squirrel population has declined. ④Although scientists have found gray squirrels to be more efficient foragers than red ones, they also note that even before the gray squirrel's arrival, Britain's red squirrel populations had a periodic tendency to die out, only to be subsequently reintroduced. ⑤Furthermore, many gray squirrels are silent carriers of a disease fatal to red squirrels.

① v1=competition

② However, v2 other factors

③ eg. ∈v2

④ Although v1, v2f

⑤ Furthermore, v2f

① ↔ ②

         ↓

         ③ 

         ↓  +  ⑤

         ④

第一题的出题点在④里的v1

第二题的题点在于通过以上论证过程找到作者的落点所在（v2）

1. It can be inferred that the author of the passage mentions the efficiency with which gray squirrels forage primarily in order to 推断+信息目的，关注句内关系

A. identify a factor that explains a certain phenomenon 无关，题干中的efficiency定位要精准，同时方向也反了，原文是个让步信息

B. call attention to an inconsistency in a particular theory 相反，严谨成分，是个让步，inconsistency属于直接取反

C. suggest that competition cannot be the factor responsible for a particular outcome 相反，起作用的是后半句

D. acknowledge a fact that appears to support a view that the authorin tends to qualify 符合

E. cite evidence that is not consistent with an early influential view about species competition 相反，同C

2. It can be inferred that the author of the passage would be most likely to agree with which of the following statements about the “early view?” 推断+作者态度

C

A. It reflects a mistaken assumption about the means by which nonnative species are introduced into ecosystems. 没有证据

B. Its basic premise is shown to be valid by the effect of American gray squirrels on Britain’s red squirrel population. 相反，人家举的是反例大哥

C. It presents a simplistic picture of the means by which species composition within ecosystems is determined. 符合

D. It can effectively explain the formation of ecosystems that contain few species but cannot adequately account for the formation of complex ecosystems. 没有证据/相反

E. It understates the importance of competition as a factor determining species composition within ecosystems. 相反