Australian researchers have discovered electroreceptors (sensory organs designed to respond to electrical field) clustered at the tip of the spiny anteater’s snout. The researchers made this discovery by exposing small areas of the snout to extremely weak electrical field and recording the transmission of resulting nervous activity to the brain. While it is true that tactile receptors, another kind of sensory organ on the anteater’s snout, can also respond to electrical stimuli, such receptors do so only in response to electrical field strengths about 1000 times greater than those known to excite electroreceptors.
Having discovered the electroreceptors, researchers are now investigating how anteaters utilize such a sophisticated sensory system. In one behavioral experiment, researchers successfully trained an anteater to distinguish between two troughs of water, one with a weak electrical field and the other with none. Such evidence is consistent with researcher’s hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey; however, researchers as yet have been unable to detect electrical signals emanating from termite mounds, where the favorite food of anteater live. Still, researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers. This ability to quickly locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
1. According to the passage, which of the following is a characteristic that distinguishes electroreceptors from tactile receptors?
2. Which of the following can be inferred about the experiment described in the first paragraph?
3. The author of the passage most probably discusses the function of tactile receptors in the first paragraph in order to ______.
4. Which of the following can be inferred about anteaters from the behavioral experiment mentioned in the second paragraph?
5. The passage suggests that the researchers mentioned in the second paragraph who observed anteaters break into a nest of ants would most likely agree with which of the following statements?
6. Which of the following, if true, would most strengthen the hypothesis mentioned in the second paragraph?
问题1选项
A.The manner in which electroreceptors respond to electrical stimulus
B.The tendency of electroreceptors to be found in clusters
C.The unusual locations in which electroreceptors are found in most species
D.The amount of electrical stimulation required to excite electroreceptors
问题2选项
A.Researchers had difficulty verifying the existence of electroreceptors in the anteater because electroreceptors respond to such a narrow range of electrical field strength.
B.Researchers found that the level of nervous activity in the anteater’s brain increased dramatically as the strength of the electrical stimulus was increased.
C.Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus.
D.Researchers found that the anteater’s tactile receptors were more easily excited by a strong electrical stimulus than were the electroreceptors.
问题3选项
A.eliminate an alternative explanation of anteaters’ response to electrical stimulus
B.highlight a type of sensory organ that has a function identical to that of electroreceptors
C.point out a serious complication in the research on electroreceptors in anteaters
D.suggest that tactile receptors assist electroreceptors in the detection of electrical signals
问题4选项
A.They are unable to distinguish between stimuli detected by their electroreceptors and stimuli detected by their tactile receptors.
B.They are unable to distinguish between the electrical signals emanating from termite mounds and those emanating from ant nests.
C.They can be trained to recognize consistently the presence of a particular stimulus.
D.They react more readily to strong than to weak stimuli.
问题5选项
A.The event they observed provides conclusive evidence that anteaters use their electroreceptors to locate unseen prey.
B.The event they observed was atypical and may not reflect the usual hunting practices of anteater.
C.Anteaters possess a very simple sensory system for use in locating prey.
D.The speed with which the anteaters located their prey is greater than what might be expected on the basis of chance alone.
问题6选项
A.Researchers are able to train anteaters to break into an underground chamber that is emitting a strong electrical signal.
B.Researchers are able to detect a weak electrical signal —emanating from the nesting chamber of an ant colony.
C.Anteaters are observed taking increasingly longer amounts of time to locate the nesting chambers of ant.
D.Anteaters are observed using various angles to break into nests of ants.
第1题:D
第2题:C
第3题:A
第4题:C
第5题:D
第6题:B
第1题:
细节事实题。根据文章第一段中的While it is true that tactile receptors, another kind of sensory organ on the anteater’s snout, can also respond to electrical stimuli, such receptors do so only in response to electrical field strengths about 1000 times greater than those known to excite electroreceptors.（然而，作为食蚁兽鼻子上的另外一种感觉器官，触觉接收器也能够对电流刺激做出反应。但是这种接收器能够做出反应的电场强度需比电感受器反应的电场强度高1000倍），可知触觉接收器和电感受器的区别在于电感受器反应的电场强度，即选项D “刺激电感受器所需的电刺激量”，符合文章内容。A选项“电感受器对电流刺激的反应方式”，B选项“电感受器集群中的存在的倾向”和C选项“在大多数物种中电感受器存在的不寻常的位置”，皆可排除。因此D选项正确。
第2题:
推理判断题。文章第一句话首先陈述了研究人员的发现，Australian researchers have discovered electroreceptors clustered at the tip of the spiny anteater’s snout（澳大利亚研究人员发现了聚集在食蚁兽鼻尖的电感受器），随后指出了发现的方式The researchers made this discovery by exposing small areas of the snout to extremely weak electrical field and recording the transmission of resulting nervous activity to the brain.（研究人员得出这一发现是通过让鼻尖的小范围接触非常微弱的电场，然后记录传送到大脑的神经活动）。由此可以推断出，在这样实验的过程中，只有食蚁兽鼻子的部分区域对这种微弱的电流产生反应，从而得出电感受器在食蚁兽鼻尖的聚集区域。与这个意思相符的是C选项“研究人员发现食蚁兽鼻子的部分区域对微弱的电流不产生反应”；A选项“由于电感受器能够产生反应的电场强度区间太窄，所有研究人员很难确定食蚁兽身体上的电感受器的存在”错误，文章中明确指出研究人员已经发现了食蚁兽鼻尖上的电感受器的存在；B选项“研究人员发现食蚁兽大脑神经活动的强度对电流强度的增加而急剧增强”和D选项“研究人员发现食蚁兽的触觉接收器比电感受器更容易对强电流做出反应”文章没有相关信息介绍，故答案选项为C。因此C选项正确。
第3题:
推理判断题。研究人员得出食蚁兽鼻尖的电感受器的发现是通过让鼻尖的小范围接触非常微弱的电场，然后记录传送到大脑的神经活动这一实验获得的，但随后文章补充到While it is true that tactile receptors, another kind of sensory organ on the anteater’s snout, can also respond to electrical stimuli, such receptors do so only in response to electrical field strengths about 1000 times greater than those known to excite electroreceptors.（虽然作为食蚁兽鼻子上的另外一种感觉器官，触觉接收器也能够对电流刺激做出反应，但是这种接收器能够做出反应的电场强度需比电感受器反应的电场强度高1000倍），由此可以推断，文章在此处提到触觉接收器的目的是为了证明在试演过程中记录到的在微电流刺激下产生的大脑神经活动是由食蚁兽鼻尖的电感受器产生的，而不是触觉接收器，故A选项“消除食蚁兽对电流刺激产生反应的另一种可能的解释”正确。B选项“强调一种与电感受器具有相同功能的一种感觉器官”，C选项“指出在食蚁兽的电感受器实验中存在的一种严重的并发情况”和D选项“指出触觉接收器在探测电流信号方面对电感受器的辅助作用”，不符合文章内容，可排除。因此A选项正确。
第4题:
细节事实题。根据文章第二段中的In one behavioral experiment, researchers successfully trained an anteater to distinguish between two troughs of water, one with a weak electrical field and the other with none. Such evidence is consistent with researcher’s hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey（在一项行为实验中，研究人员成功地将一只食蚁兽训练得能够区分具有微电场和没有电场的水槽。这一证据也正好印证了研究人员的一个假设：食蚁兽通过电感受器来探测猎物发出的电流信号），可以推断出C选项“食蚁兽能够通过训练具备辨别特定刺激物存在的能力”正确。A选项“食蚁兽不能区分由电感受器和触觉接收器探测到的电流刺激”，B选项“食蚁兽不能区分从白蚁丘和从蚁巢中发出的电流信号”和D选项“相比微电流刺激，食蚁兽更容易对强电流刺激做出反应”文章中均没有相关信息的介绍，故答案为C选项。因此C选项正确。
第5题:
推理判断题。根据第二段最后一句话This ability to quickly locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.（根据研究人员的看法，快速定位无法看见的猎物的能力表明，食蚁兽在定位蚂蚁巢穴时，是运用了它们的电感受器的），由此可知，C选项“食蚁兽在定位蚂蚁巢穴时，没有借用电感受器”与原文意思不符，故排除。D选项“食蚁兽定位猎物的速度要明显快于预期中仅凭偶然机会获取猎物的速度”，意思相当于是食蚁兽通常是通过电感受器来定位猎物而不是通过偶然的机会（碰运气）来寻找猎物，故为答案选项。根据文章第二段中的Such evidence is consistent with researcher’s hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey（食蚁兽使用其位于鼻子简短狭小区域的电感受器来定位猎物的具体位置只是研究人员的假设并未得到最终确定性的证实），A选项“决定性证据”与这句话是相矛盾的，可排除；根据第二段中的Still, researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers.（研究人员所观察到的食蚁兽将鼻子伸进蚂蚁巢穴，并快速定位蚂蚁巢穴的位置）可知，反映了食蚁兽习惯性的捕食习惯，B选项“他们观察到的事件是非典型性的，可能也无法反映出食蚁兽的惯例捕食习惯”与原文意思表达相反，故排除。因此D选项正确。
第6题:
推理判断题。文章第二段中的Such evidence is consistent with researcher’s hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey（证据也正好印证了研究人员的一个假设：食蚁兽通过电感受器来探测猎物发出的电流信号）可知研究人员的假设是：食蚁兽通过电感受器来探测猎物发出的电流信号。B选项“研究人员探测到从蚂蚁巢穴中发出的微电流信号”，如果被证明正确，则可以进一步说明食蚁兽通过电感受器来探测猎物发出的电流信号；A选项“研究人员能够训练食蚁兽闯入发出强烈电流信号的地下洞室”，强调的是对食蚁兽的训练所能达到的效果，对研究人员的假设没有加强作用；C选项“食蚁兽被观察到定位蚁巢膛室所需的时间越来越长”和D选项“食蚁兽被观察到从不同的角度闯入蚁巢”对研究人员的假设起削弱作用，故答案为B选项。因此B选项正确。
