首页
登录
职称英语
One of the greatest mysteries in the study of Cetacea [aquatic mammals] has a
One of the greatest mysteries in the study of Cetacea [aquatic mammals] has a
游客
2025-05-10
9
管理
问题
One of the greatest mysteries in the study of Cetacea [aquatic mammals] has always been that the creatures found in the stomachs of toothed whales show no teeth marks. Now a University of California at Santa Cruz professor thinks he may have solved the enigma with what he calls the "big bang" theory of cetacean predation.
Ken Norris, natural history professor, believes that rather than use their teeth to attack their victims, toothed whales stun their prey with intense bursts of sound. He points out that all 68 species of odontocetes (a sub-order that includes dolphins) use sound to locate their victims, and suggests this ability may have evolved to the point where it could be used as a weapon.
Millions of years ago, the ancestors of whales had a narrow tapered jaw, streamlined for speed and bristling with long rows of sharp teeth. Today odontocetes are not adapted to surprising their prey or trapping it quickly. Most are more bulky than their forebearers; their teeth are short and unevenly spaced when they exist at all. Norris suggests that because of their sonar ability, whales’ teeth have become vestigial, like the human appendix.
It is difficult to test the big bang theory because in captivity, cetaceans tend to moderate their sonar so as not to deafen other creatures in their small, highly reflective tanks. Dolphins are known to politely turn off their echolocation systems when passing one another. And in the wild it’s hard to tell whether a sound came from a nearby animal or form another very far away.
But Norris points to the male narwhal as tacit proof of his theory. This whale has no teeth, and the single spiral tusk that extends about eight feet in front of him would seem to be more of an impediment than an aid in catching shrimp, his preferred feed. "You look at these animals and you wonder what’s going on." [br] It can be concluded from the passage that the "big bang" theory is ______.
选项
A、a fact
B、a disproved hypothesis
C、an unsupported opinion
D、an idea with some supporting evidence
答案
D
解析
第四段第一句"It is difficult to test the big bang theory because in captivity",第五段第一句"But Norris points to the male narwhal as tacit proof of his theory",综合起来也就是说该理论难以验证但有一些支持性的证据。
转载请注明原文地址:https://tihaiku.com/zcyy/4070043.html
相关试题推荐
GeniusThegreatestresultsinlifeareattainedbysimplemeans,andthe
GeniusThegreatestresultsinlifeareattainedbysimplemeans,andthe
GeniusThegreatestresultsinlifeareattainedbysimplemeans,andthe
OneofthegreatestmysteriesinthestudyofCetacea[aquaticmammals]hasa
OneofthegreatestmysteriesinthestudyofCetacea[aquaticmammals]hasa
Heisahypocrite,aliar,athief—______,heisthegreatestdevilIeverknow.
Althoughvocalcordsarelackingincetaceans,phonationisundoubtedlycent
Althoughvocalcordsarelackingincetaceans,phonationisundoubtedlycent
Wemusttrytouseourintellect______.A、tothegreatestadvantageB、forthemo
ThegreatestcelestialobservatoryofNeolithictimes,stonehenge,is(awork)o
随机试题
UnitTestingandComponentTesting--Asoftwareunitrepresentsasmallunitof
Nottoomanydecadesagoitseemed"obvious"bothtothegeneralpublicand
TypesofClimateClimateisthecombinationoftem
药物治疗不稳定型心绞痛下列哪项不正确?()A.氯吡格雷 B.β受体阻滞剂
下列关于隧道支护的说法,正确的是()。A.喷射混凝土分为干喷和湿喷现基本采用干喷
房屋产权人甲某,委托房地产中介服务机构丙公司将其房屋一次性出租,经丙公司联系
肺炎链球菌肺炎X线检查的表现是()A.早期可见病变部位的密度均匀影 B.
各种运输方式内外部的各个方面的构成和联系,就是( )。 A.运输系统
(2018年5月)培训实施体系包括()A.内培 B.课堂培训 C.拓展培训
我国工资、薪金所得,适用的个人所得税税率为()。A、3%~35% B、3%~4
最新回复
(
0
)