GRE-90-04-T21

paopao

Traditionally, pollination by wind has been viewed as a reproductive process marked by random events in which the vagaries (vagary: an erratic, unpredictable, or extravagant manifestation, action, or notion) of the wind are compensated for by the generation of vast quantities of pollen, so that the ultimate production of new seeds is assured at the expense of producing much more pollen than is actually used. Because the potential hazards pollen grains are subject to as they are transported over long distances are enormous, wind-pollinated plants have, in the view above, compensated for the ensuing loss of pollen through happenstance by virtue of producing an amount of pollen that is one to three orders of magnitude greater than the amount produced by species pollinated by insects.老观点：风媒植物多产花粉。原因

However, a number of features that are characteristic of wind-pollinated plants reduce pollen waste.（风媒植物减少花粉浪费） For example, many wind-pollinated species fail to release pollen when wind speeds are low or when humid conditions prevail. （风速低，湿度大时，不产）Recent studies suggest another way in which species compensate for the inefficiency of wind pollination. These studies suggest that species frequently take advantage of (take advantage of: v.利用) the physics of pollen motion by generating specific aerodynamic （aerodynamic adj.空气动力学的）environments within the immediate vicinity of their female reproductive organs. It is the morphology of these organs that dictates the pattern of airflow disturbances through which pollen must travel. The speed and direction of the airflow disturbances can combine with the physical properties of a species’ pollen to produce a species-specific pattern of pollen collision on the surfaces of female reproductive organs. Provided that these surfaces are strategically located, the consequences of this combination can significantly increase the pollen-capture efficiency of a female reproductive organ (reproductive organ: 生殖器).另一种办法：在雌性繁殖器官附近传播花粉。

风媒植物减少花粉浪费。一是在风速低，湿度大时，不产花粉，二是在雌性生殖器官附近产花粉

A critical question that remains to be answered is whether the morphological attributes of the female reproductive organs of wind-pollinated species are evolutionary adaptations to wind pollination or are merely fortuitous（ fortuitous adj.偶然的, 幸运的）. （问题：这一生态现象是适应性的还是偶然的，承上启下）A complete resolution of the question is as yet impossible since adaptation must be evaluated for each species within its own unique functional context. However, it must be said that, while evidence of such evolutionary adaptations does exist in some species, one must be careful about attributing morphology to adaptation. For example, the spiral arrangement of scale-bract complexes on ovule-bearing pine cones, where the female reproductive organs of conifers are located, is important to the production of airflow patterns that spiral over the cone’s surfaces, thereby passing airborne pollen from one scale to the next. However, these patterns cannot be viewed as an adaptation to wind pollination because the spiral arrangement occurs in a number of non-wind-pollinated plant lineages and is regarded as a characteristic of vascular plants, of which conifers are only one kind, as a whole. Therefore, the spiral arrangement is not likely to be the result of a direct adaptation to wind pollination.提出问题：这一生态现象是适应性的还是偶然的？没法完全回答。松果为例，SA在非风媒的松果中也有。否定了是适应的说法。

21.   The author of the passage is primarily concerned with discussing主题题，我选了A

(A)  the current debate on whether the morphological attributes of wind-pollinated plants are evolutionary adaptations

(B) the kinds of airflow patterns that permit wind-pollinated plants to capture pollen most efficiently比较点，细节

(C) the ways in which the reproductive processes of wind-pollinated plants are controlled by random events

(D) a recently proposed explanation of a way in which wind-pollinated plants reduce pollen waste（D）

(E) a specific morphological attribute that permits one species of wind-pollinated plant to capture pollen

这题我做错了选A 但是感觉A是对的 根据

A critical question that remains to be answered is whether the morphological attributes of the female reproductive organs of wind-pollinated species are evolutionary adaptations to wind pollination or are merely fortuitous

而不是D所说的a recently proposed explanation

另外 请教在做列举题时我通常一题要花2分钟  能找到相应的地方 只是有些题目选项的改写我需要一一对应 这样花的时间特别多

请问大家有没有什么更好的办法 时间少准确度的办法来对付列举题

谢谢

paopao

请大家帮助 谢谢

weiyu

I am exhausted, I will post tomorrow.

paopao

weiyu, Thank you very much. Have a good rest first.

weiyu

G90-04-B-L

Traditionally, pollination by wind has been viewed as a reproductive process marked by random events in which the vagaries (vagary: an erratic, unpredictable, or extravagant manifestation, action, or notion) of the wind are compensated for by the generation of vast quantities of pollen, so that the ultimate production of new seeds is assured at the expense of producing much more pollen than is actually used. Because the potential hazards pollen grains are subject to as they are transported over long distances are enormous, wind-pollinated plants have, in the view above, compensated for the ensuing loss of pollen through happenstance by virtue of producing an amount of pollen that is one to three orders of magnitude greater than the amount produced by species pollinated by insects. (介绍一个风授粉的现象，属于background或context)

However, a number of features that are characteristic of wind-pollinated plants reduce pollen waste. For example, many wind-pollinated species fail to release pollen when wind speeds are low or when humid conditions prevail. Recent studies suggest another way in which species compensate for the inefficiency of wind pollination. These studies suggest that species frequently take advantage of (take advantage of: v.利用) the physics of pollen motion by generating specific aerodynamic environments within the immediate vicinity of their female reproductive organs. It is the morphology of these organs that dictates the pattern of airflow disturbances through which pollen must travel. The speed and direction of the airflow disturbances can combine with the physical properties of a species’ pollen to produce a species-specific pattern of pollen collision on the surfaces of female reproductive organs. Provided that these surfaces are strategically located, the consequences of this combination can significantly increase the pollen-capture efficiency of a female reproductive organ (reproductive organ: 生殖器). (讲了2个减少风授粉损失的features)

A critical question that remains to be answered is whether the morphological attributes of the female reproductive organs of wind-pollinated species are evolutionary adaptations to wind pollination or are merely fortuitous. A complete resolution of the question is as yet impossible since adaptation must be evaluated for each species within its own unique functional context. However, it must be said that, while evidence of such evolutionary adaptations does exist in some species, one must be careful about attributing morphology to adaptation. For example, the spiral arrangement of scale-bract complexes on ovule-bearing pine cones, where the female reproductive organs of conifers are located, is important to the production of airflow patterns that spiral over the cone’s surfaces, thereby passing airborne pollen from one scale to the next. However, these patterns cannot be viewed as an adaptation to wind pollination because the spiral arrangement occurs in a number of non-wind-pollinated plant lineages and is regarded as a characteristic of vascular plants, of which conifers are only one kind, as a whole. Therefore, the spiral arrangement is not likely to be the result of a direct adaptation to wind pollination. (讲了2段的第二个feature不属于进化论结果)

21.   The author of the passage is primarily concerned with discussing

(A) the current debate on whether the morphological attributes of wind-pollinated plants are evolutionary adaptations (3段内容)

(B) the kinds of airflow patterns that permit wind-pollinated plants to capture pollen most efficiently (2段的那个study内容)

(C) the ways in which the reproductive processes of wind-pollinated plants are controlled by random events（1段内容）

(D) a recently proposed explanation of a way in which wind-pollinated plants reduce pollen waste （2，3段的内容，是主题）（D）

(E) a specific morphological attribute that permits one species of wind-pollinated plant to capture pollen（3段细节）