A special mucous coating that serves as a chemical camouflage allows clown fish to live among the deadly tentacles of the unsuspecting sea anemone. Utterly dependent on this unlikely host for protection from predators, clown fish have evolved in isolated communities, a pattern that has led to unusual behavioral adaptations.
The rigidly defined hierarchy of each clown-fish community is dominated by a “monogamous” breeding pair consisting of the largest fish, a female, and the next largest, a male, attended by a fixed large number of sexually immature fish ranging in size from large to tiny. A remarkable adaptation is that the development of these juveniles is somehow arrested until the hierarchy changes; then they grow in lockstep, maintaining their relative sizes. While the community thus economizes on limited space and food resources, life is risky for newly spawned clown fish. On hatching, the hundreds of larvae drift off into the plankton. If, within three weeks, the defenseless larval clown fish locates a suitable anemone (either by pure chance or perhaps guided by chemicals secreted by the anemone), it may survive. However, if an anemone is fully occupied the resident clown fish will repel any newcomer.
Though advantageous for established community members, the suspended and staggered maturation of juveniles might seem to pose a danger to the continuity of the community there is only one successor for two breeding fish. Should one of a pair die, the remaining fish cannot swim off in search of a mate, nor is one likely to arrive. It would seem inevitable that reproduction must sometimes have to halt, pending the chance arrival and maturation of a larval fish of the appropriate sex.
This, however, turned out not to be the case. In experiments, vacancies have been contrived by removing an established fish from a community. Elimination of the breeding male triggers the prompt maturation of the largest juvenile. Each remaining juvenile also grows somewhat, and a minuscule newcomer drops in from the plankton. Removal of the female also triggers growth in all remaining fish and acceptance of a newcomer, but the female is replaced by the adult male. Within days, the male’s behavior alters, and the physiological transformation is complete within a few months. Thus, whichever of the breeding pair is lost, a relatively large juvenile can fill the void, and reproduction can resume with a minimal loss of time. Furthermore, the new mate has already proved its ability to survive.
This transformation of a male into a female, or protandrous hermaphroditism, is rare among reef fish. The more common protogynous hermaphroditism, where females change into males does not occur among clown fish. An intriguing question for further research is whether a juvenile clown fish can turn directly into a female or whether it must function as a male.
1. The passage is primarily concerned with ______.
2. It can be inferred from the passage that clown fish is able to survive in close association with the sea anemone because the ______.
3. It can be inferred from the passage that sex change would have been less necessary for the clown fish if ______.
4. All of the following are characteristics of the “rigidly defined hierarchy” of the clown fish community EXCEPT ______.
5. Which of the following statements about newly hatched clown fish can be inferred from the passage?
6. Which of the following does not agree with the author’s explanation of the advantage of hermaphroditism for clown fish?
问题1选项
A.analyzing the mutually advantageous relationship between two species
B.comparing two forms of hermaphroditism among clown fish
C.describing and explaining aspects of clown fish behavior
D.outlining proposed research on clown-fish reproduction
问题2选项
A.sea anemone cannot detect the presence of the clown fish
B.tentacles of the sea anemone cannot grasp the slippery clown fish
C.sea anemone prefers other prey
D.clown fish does not actually come within the range of the sea anemone’s tentacles
问题3选项
A.the male clown fish were larger than the female
B.each sea anemone were occupied by several varieties of clown fish
C.many mature clown fish of both sexes occupied each sea anemone
D.juvenile clown fish had a high mortality rate
问题4选项
A.at any time only one female clown fish can be reproductively active
B.the mature clown fish are monogamous
C.the maximum number of clown fish is fixed
D.there are equal numbers of male juveniles and female juveniles
问题5选项
A.They develop rapidly.
B.They remain close to the a anemone occupied by their parents.
C.They are more sensitive to chemical signals than are adult clown fish.
D.They are not protected by their parents.
问题6选项
A.The number of individuals in a clown fish community fluctuates significantly.
B.Adult clown fish frequently cannibalize their young.
C.Juvenile clown fish rarely reach maturity.
D.Clown-fish communities are capable of efficiently recruiting solitary adult clown fish.
第1题:C
第2题:A
第3题:C
第4题:D
第5题:D
第6题:D
第1题:
【选项释义】
The passage is primarily concerned with ____. 这篇文章主要是____。
A. analyzing the mutually advantageous relationship between two species A. 分析两个物种之间的互利关系
B. comparing two forms of hermaphroditism among clown fish B. 比较小丑鱼雌雄同体的两种形式
C. describing and explaining aspects of clown fish behavior C. 描述和解释小丑鱼的行为
D. outlining proposed research on clown-fish reproduction D. 概述对小丑鱼繁殖的研究建议
【考查点】主旨大意题
【解题思路】文章第一段向读者介绍了小丑鱼的一些独特的行为适应，因为它们依赖宿主（海葵）的保护；第二段解释了小丑鱼群落的等级制度，以及在等级发生变化之前的生长适应。作者还讨论了由于宿主海葵的空间和食物限制，新产卵的小丑鱼的风险；第三段质疑小丑鱼群落的可持续性，强调了其繁殖方法的潜在问题，因为两条繁殖鱼只有一个继承人；最后一段描述了小丑鱼群落的实验结果，揭示了当一条繁殖鱼被消灭时，最大的幼鱼成熟并可以恢复繁殖。小丑鱼幼鱼是可以直接变成雌性，还是必须先变成雄性，这个谜团还有待进一步研究。综上可知，文章通篇都在介绍小丑鱼的行为分类，生殖繁育等习性，故C选项“描述和解释小丑鱼的行为”正确。
【干扰项排除】
A选项“分析两个物种之间的互利关系”文章只是提到小丑鱼会居住在海葵中间，但并没有提到两者的互利关系，属于无中生有；
B选项“比较小丑鱼雌雄同体的两种形式”这并不文章的主要内容，属于以偏概全；
D选项“概述对小丑鱼繁殖的研究建议”文章没有重点概述未来的研究，它只在最后一句话提到了进一步研究的建议，属于以偏概全。
第2题:
【选项释义】
It can be inferred from the passage that clown fish is able to survive in close association with the sea anemone because the ____. 从文中可以推断出，小丑鱼之所以能够与海葵紧密地生活在一起，是因为____。
A. sea anemone cannot detect the presence of the clown fish A. 海葵无法发现小丑鱼的存在
B. tentacles of the sea anemone cannot grasp the slippery clown fish B. 海葵的触手抓不住滑溜溜的小丑鱼
C. sea anemone prefers other prey C. 海葵更喜欢其他猎物
D. clown fish does not actually come within the range of the sea anemone’s tentacles D. 小丑鱼实际上没有进入海葵触手的捕食范围
【考查点】推理判断题
【解题思路】文章第一段第一句讲“一种特殊的粘液涂层作为化学伪装，使小丑鱼能够生活在毫无戒心的海葵的致命触手中（A special mucous coating that serves as a chemical camouflage allows clown fish to live among the deadly tentacles of the unsuspecting sea anemone.）。”根据关键词“a chemical camouflage”和“unsuspecting”可推断，小丑鱼的伪装使海葵无法察觉小丑鱼的存在，这就是为什么小丑鱼能够与海葵生活在一起的原因，故A选项正确。
【干扰项排除】
B选项“海葵的触手抓不住滑溜溜的小丑鱼”文章中没有任何信息表明海葵的触手不能抓住滑溜的小丑鱼，属于无中生有；
C选项“海葵更喜欢其他猎物”文章没有提到任何关于海葵喜欢其他猎物或将其他猎物纳入其饮食的事情，属于无中生有；
D选项“小丑鱼实际上没有进入海葵触手的捕食范围”与小丑鱼生活在“海葵的致命触手中”这一说法相矛盾，属于曲解原文。
第3题:
【选项释义】
It can be inferred from the passage that sex change would have been less necessary for the clown fish if ____. 从文中可以推断出，如果____，小丑鱼就不需要变性。
A. the male clown fish were larger than the female A. 雄性小丑鱼比雌性大
B. each sea anemone was occupied by several varieties of clown fish B. 每只海葵被几种小丑鱼占据
C. many mature clown fish of both sexes occupied each sea anemone C. 每只海葵上都有许多成熟的雌雄小丑鱼
D. juvenile clown fish had a high mortality rate D. 小丑鱼幼鱼的死亡率很高
【考查点】推理判断题
【解题思路】文章第三段最后一句讲“似乎不可避免的是，繁殖有时必须停止，等待合适性别的幼鱼的到来和成熟（It would seem inevitable that reproduction must sometimes have to halt, pending the chance arrival and maturation of a larval fish of the appropriate sex.）。”由此可推断，如果在海葵中有许多成熟的雌雄小丑鱼，那么当雌鱼或雄鱼死去时，找不到替代者的可能性就会变小，因此雄鱼不需要通过变性成为雌鱼，C选项正确。
【干扰项排除】
A选项“雄性小丑鱼比雌性大”根据原文可知，改变性别的需要是由于一对伴侣中缺少了一只雌性，而不是雄性的体型，属于曲解原文；
B选项“每只海葵被几种小丑鱼占据”根据文中的信息，一个海葵中小丑鱼的多样性并不影响性别改变的需要，属于答非所问；
D选项“小丑鱼幼鱼的死亡率很高”可能会增加而不是减少性别变化的必要性，因为它会减少潜在的成熟鱼的数量，以取代失去的繁殖者，属于反向干扰。
第4题:
【选项释义】
All of the following are characteristics of the “rigidly defined hierarchy” of the clown fish community EXCEPT ____. 下列各项都是小丑鱼群落“等级森严”的特征，除了____。
A. At any time only one female clown fish can be reproductively active A. 在任何时候都只有一条雌性小丑鱼具有繁殖能力
B. The mature clown fish are monogamous B. 成熟的小丑鱼是一夫一妻制的
C. The maximum number of clown fish is fixed C. 小丑鱼的最大数量是固定的
D. There are equal numbers of male juveniles and female juveniles D. 雄性小丑鱼和雌性小丑鱼的数量相等
【考查点】细节事实题
【解题思路】根据关键词“rigidly defined hierarchy”定位到第二段第一句“每个小丑鱼群落严格定义的等级制度是由‘一夫一妻制’的繁殖对主导的，其中包括最大的鱼——一条雌鱼和第二大的鱼——一条雄鱼，还有固定数量的从大到小不等的性未成熟鱼（The rigidly defined hierarchy of each clown-fish community is dominated by a ‘monogamous’ breeding pair consisting of the largest fish, a female, and the next largest, a male, attended by a fixed large number of sexually immature fish ranging in size from large to tiny.）。”由此可知，A、B、C选项均符合原文，只有D选项“雄性小丑鱼和雌性小丑鱼的数量相等”没有提及，故D选项正确。
【干扰项排除】
根据以上分析可知，A、B、C选项的表述均与原文一致，属于答非所问。
第5题:
【选项释义】
Which of the following statements about newly hatched clown fish can be inferred from the passage? 下面哪个关于刚孵出的小丑鱼的陈述可以从文章中推断出来？
A. They develop rapidly. A. 它们发育迅速。
B. They remain close to the anemone occupied by their parents. B. 它们一直靠近父母占据的海葵。
C. They are more sensitive to chemical signals than are adult clown fish. C. 它们比成年小丑鱼对化学信号更敏感。
D. They are not protected by their parents. D. 它们不受父母的保护。
【考查点】推理判断题
【解题思路】根据关键词“hatched”定位到第二段最后几句“孵化后（On hatching），数以百计的幼虫漂向浮游生物。如果在三周内，毫无防备的小丑鱼幼虫找到了合适的海葵（要么是纯粹的偶然，要么是海葵分泌的化学物质的引导），它就有可能存活下来。然而，如果海葵被完全占据，常驻的小丑鱼会排斥任何新来的人。”也就是说，新产卵的小丑鱼的生活却充满风险（life is risky for newly spawned clown fish），三周内找到合适的海葵才可以生存下去，它们没有父母的保护，故D选项正确。
【干扰项排除】
A选项“它们发育迅速”文章讨论了等级变化时幼鱼如何生长，但它没有具体说明这种生长是快速的，属于无中生有；
B选项“它们一直靠近父母占据的海葵”与文中的说法相矛盾，文中说“毫无防备的小丑鱼幼虫找到了合适的海葵”，没有提到它们会一直靠近父母的海葵，属于曲解原文；
C选项“它们比成年小丑鱼对化学信号更敏感”文中提到，幼鱼可能会通过化学信号找到海葵，但并没有说它们对这些信号比成年鱼更敏感，属于曲解原文。
第6题:
【选项释义】
Which of the following does not agree with the author’s explanation of the advantage of hermaphroditism for clown fish? 以下哪项与作者对小丑鱼雌雄同体优势的解释不相符？
A. The number of individuals in a clown fish community fluctuates significantly. A. 小丑鱼群落个体数量波动显著。
B. Adult clown fish frequently cannibalize their young. B. 成年小丑鱼经常吃掉它们的幼鱼。
C. Juvenile clown fish rarely reach maturity. C. 幼年小丑鱼很少长到成年。
D. Clown-fish communities are capable of efficiently recruiting solitary adult clown fish. D. 小丑鱼群体能够有效地招募孤独的成年小丑鱼。
【考查点】推理判断题
【解题思路】文章中解释了小丑鱼群体的独特性：他们生活在分离的社区，靠海葵的保护生存，而且，他们之间的生育会受到一种严格的等级制度的控制。当成年鱼（雌鱼或雄鱼）消失后，最大的未成年鱼会变成雄性，然后再变成雌性来填补空缺。这种独特的适应性使得小丑鱼群体动态平衡，保证了生育的连续性。然而，如果小丑鱼群体能够有效地招募孤独的成年小丑鱼，那么他们内部的这种性别转变就不再那么必要了，因此，D选项与作者对雌雄两性优势的解释最不一致。
【干扰项排除】
A选项“小丑鱼群落个体数量波动显著”这并不冲突，反而是由于小丑鱼的这种独特性质，它们能够通过性别转变来应对群落数量的变化，属于曲解原文；
B选项“成年小丑鱼经常吃掉它们的幼鱼”这同样并不冲突，因为就算最大的未成年小丑鱼被同类食用了，剩余的小丑鱼仍然可以通过变成雄性再变成雌性来填补空缺，属于曲解原文；
C选项“幼年小丑鱼很少长到成年”在此情况下，群落系统依然可以运作，因为如果成年鱼死亡，那么最大的未成年鱼仍然可以成为替代者，属于曲解原文。
