分析了一篇文章，杨继20，－逻辑结构看得还不够简单明了，选择答案也不够一针见血。贴上来，希望大家共同探讨，做阅读的思维过程。

以下是我多文章的分析，希望大家以此来讨论，我相信会对大家进一步养成RC的思维习惯，和答题习惯，提高速度有帮助。

我的问题是读得慢，简直像精读，才能作对题目，也希望NN给点帮助，看看我是哪出问题了，应该怎么提高

Passage 20 (20/63)

Species interdependence in nature confers many benefits on the species involved, but it can also become a point of weakness when one species involved in the relationship is affected by a catastrophe. Thus, flowering plant species dependent on insect pollination, as opposed to self-pollination or wind pollination, could be endangered when the population of insect-pollinators is depleted by the use of pesticides.

（第一段：物种的相互依赖使受益很多互相依赖的物种，但是这种相互依赖的的缺点：当其中一种物种受到灾难时体现。例如花粉的物种）

In the forests of New Brunswick（名字要记住，简记为NB-举例，预期下面要出细节题）, for example, various pesticides have been sprayed in the past 25 years in efforts to control the spruce budworm, an economically significant pest. Scientists have now investigated the effects of the spraying of Matacil, one of the anti-budworm agents that is least toxic
            （比较举例分析的这种spraying和其它的spraying的关系，预期有比较关系，做推断的题）to insect-pollinators. They studied Matacil’s effects on insect mortality in a wide variety of wild insect species and on plant
                    fecundity, expressed as the percentage of the total flowers on an individual plant that actually developed fruit and bore seeds.
            （我读出要授粉后才会产生果实，所以用果实的percentage来读出fecundity这个词和pollination产生关系，那么逻辑图: spraying 影响insect-pollinator,主要是减少，－>减少授粉－>果实减少）They found that the most pronounced mortality after the spraying of Matacil occurred among the smaller bees and one family of flies, insects that were all important pollinators of numerous species of plants growing beneath the tree canopy of forests. The fecundity of plants in one common indigenous species, the red-osier dogwood, was significantly reduced in the sprayed areas as compared to that of plants in control plots where Matacil was not sprayed. This species is highly dependent on the insect-pollinators most vulnerable to Matacil. The creeping dogwood, a species similar to the red-osier dogwood, but which is pollinated by large bees, such as bumblebees, showed no significant decline in fecundity. Since large bees are not affected by the spraying of Matacil, these results add weight to the argument that spraying where the pollinators are sensitive to the pesticide used decreases plant fecundity.

（第二段：NB用spraying的M情况举例：两方面对比受影响和未受影响的物种论述，得到（加强）结论：对于spraying敏感的授粉对象，spraying后植物多样行下降）

The question of whether the decrease in plant fecundity caused by the spraying of pesticides actually causes a decline in the overall population of flowering plant species still remains unanswered.
            （第三段的中心意思）Plant species dependent solely on seeds for survival or dispersal are obviously more vulnerable to any decrease in plant fecundity that occurs, whatever its cause. If, on the other hand, vegetative growth and dispersal (by means of shoots or runners) are available as alternative reproductive strategies for a species, then decreases in plant fecundity may be of little consequence. The fecundity effects described here are likely to have the most profound impact on plant species with all four of the following characteristics（列举一般下面会出题）: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species.
            Perhaps we should give special attention to the conservation of such plant species since they lack key factors in their defenses against the environmental disruption caused by pesticide use.

（第三段：对前面的结论提出质疑（逻辑结构严密的体现）：由于spraying的作用使植物多样性下降是否真的使整体的花粉植物的总数下降？－>会受到影响的物种/不会受到影的物种－>物种多样性易受影响的植物的四个特点－>对保护物种的建议。其实这段主要还是在论述关于易受影响的物种。对于前面的观点－相互依赖的物种的弱点引申出的话题）

1.    Which of the following best summarizes the main point of the passage?

(A) Species interdependence is a point of weakness for some plants, but is generally beneficial to insects involved in pollination.

(B) Efforts to control the spruce budworm have had deleterious effects on the red-osier dogwood.

(C) The used of pesticides may be endangering certain plant species dependent on insects for pollination.

(D) The spraying of pesticides can reduce the fecundity of a plant species, but probably does not affect its overall population stability.（C）

(E) Plant species lacking key factors in their defenses against human environmental disruption will probably become extinct.

2.    According to the author, a flowering plant species whose fecundity has declined due to pesticide spraying may not experience an overall population decline if the plant species can do which of the following?

(A) Reproduce itself by means of shoots and runners.

(B) Survive to the end of the growing season.

(C) Survive in harsh climates.

(D) Respond to the fecundity decline by producing more flowers.（A）

(E) Attract large insects as pollinators.

3.    The passage suggests that the lack of an observed decline in the fecundity of the creeping dogwood strengthens the researchers conclusions regarding pesticide use because the

(A) creeping dogwood is a species that does not resemble other forest plants

(B) creeping dogwood is a species pollinated by a broader range of insect species than are most dogwood species

(C) creeping dogwood grows primarily in regions that were not sprayed with pesticide, and so served as a control for the experiment

(D) creeping dogwood is similar to the red-osier dogwood, but its insect pollinators are known to be insensitive to the pesticide used in the study（D）

(E) geographical range of the creeping dogwood is similar to that of the red-osier dogwood, but the latter species relies less on seeds for reproduction

4.    The passage suggests that which of the following is true of the forest regions in New Brunswick sprayed with most anti-budworm pesticides other than Matacil?(可定位的细节题)

(A) The fecundity of some flowering plants in those regions may have decreased to an even greater degree than in the regions where Matacil is used.

（M是least toxic的spraying，通过study M’s effect found fecundity受影响和未受影响的species, 结论：授粉者容易受到pesticide影响的会减少植物多样性）。

(B) Insect mortality in those regions occurs mostly among the larger species of insects, such as bumblebees.

(C) The number of seeds produced by common plant species in those regions is probably comparable to the number produced where Matacil is sprayed.（seed是第三段提到的内容，第二段还没有出现，排除）

(D) Many more plant species have become extinct in those regions than in the regions where Matacil is used.（A）

(E) The spruce budworm is under better control in those regions than in the regions where Matacil is sprayed.

5.    It can be inferred that which of the following is true of plant fecundity as it is defined in the passage?（答案一般出现在这个词出现第一次的地方）

(A) A plant’s fecundity decreases as the percentage of unpollinated flowers on the plant increases.（
                    原文的论述也有percentage，要小心，比较
                    关系叙述是否正确，比较关系容易出逻辑推理，一般是考点，此处是和原文表述同一个意思，但是时相反的论述）

(B) A plant’s fecundity decreases as the number of flowers produced by the plant decreases.

(C) A plant’s fecundity increases as the number of flowers produced by the plant increases.

(D) A plant’s fecundity is usually low if the plant relies on a small number of insect species for pollination.（A）

(E) A plant’s fecundity is high if the plant can reproduce quickly by means of vegetative growth as well as by the production of seeds.

6.    It can be inferred from the passage that which of the following plant species would be LEAST likely to experience a decrease in fecundity as a result of the spraying of a pesticide not directly toxic to plants?

(A) A flowering tree pollinated by only a few insect species

(B) A kind of insect-pollinated vine producing few flowers

(C) A wind-pollinated flowering tree that is short-lived

(D) A flowering shrub pollinated by a large number of insect species（C）

(E) A type of wildflower typically pollinated by larger insects

7.    Which of the following assumptions most probably underlies the author’s tentative recommendation in lines 51-54?

(A) Human activities that result in environmental disruption should be abandoned.

(B) The use of pesticides is likely to continue into the future.

(C) It is economically beneficial to preserve endangered plant species.

(D) Preventing the endangerment of a species is less costly than trying to save an already endangered one.（B）

(E) Conservation efforts aimed at preserving a few well-chosen species are more cost-effective than are broader-based efforts to improve the environment.

Summary：逻辑结构：

提出观点（关于植物依赖性）－>进一步阐述，加强结论－>提出质疑，分析提出建议