首页
登录
职称英语
The ability of falling cats to right themselves in midair and land on their
The ability of falling cats to right themselves in midair and land on their
游客
2023-11-20
20
管理
问题
The ability of falling cats to right themselves in midair and land on their feet has been a source of wonder for ages. Biologists long regarded it as an example of 【C1】______ by natural selection, but for physicists it bordered on the miraculous. Newton’s laws of motion 【C2】______ that the total amount of spin of a body cannot change 【C3】______ an external torque speeds it up or slows it down. If a cat has no spin when it is released and experiences no external torque, it ought not to be able to 【C4】______ as it falls.
In the speed of its execution, the 【C5】______ of a tumbling cat resembles a magician’s trick. The gyrations of the cat in midair are 【C6】______ fast for the human eye to follow, so the process is obscured.【C7】______ the eye must be speeded up, or the cat’s fall slowed down for the phenomenon to be observed. A century ago the former was accomplished 【C8】______ high-speed photography using equipment now 【C9】______ in any pharmacy. But in the nineteenth century the 【C10】______ on film of a falling cat constituted a scientific experiment.
The experiment was described in a paper presented to the Paris Academy in 1894. Two sequences of twenty photographs【C11】______ one from the side and one from behind, 【C12】______ a white cat in the act of righting itself. Grainy and quaint 【C13】______ they are, the photos show that the cat was dropped upside down, with no initial spin, and still landed on its feet. Careful analysis of the photos reveals the secret. As the Cat rotates the front of its body 【C14】______ , the rear and tail twist counterclockwise, 【C15】______ the total spin remains zero, 【C16】______ Newton’s laws. Halfway down, the cat pulls in its legs before reversing its twist and then extends them again, 【C17】______ the desired end result. The explanation was that while no body can acquire spin without torque, a flexible one can readily change its 【C18】______ . Cats know this instinctively, but scientists could not be sure how it happened 【C19】______ they increased the speed of their 【C20】______ a thousandfold. [br] 【C16】
选项
A、in accord with
B、in accord to
C、by accord with
D、by accord to
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3204573.html
相关试题推荐
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
Noonecandenythatpesticidehaveimprovedtheabilityoffarmerstobrin
随机试题
Themarketinvestigationisindispensabletosalespromotion.Theyareascl
SherlockHolmesisafictionalcharactercreatedbyBritishauthorandphysic
在控制检查风险时,注册会计师应当采取的有效措施是()。A.调高重要性水平 B.
根据《城乡规划法》,制定近期建设规划的依据不包括( )。A.土地利用总体规划
(2020年真题)( )对证券公司实施《证券公司全面风险管理规范》的情况进行自
关于实收资本的核算说法,正确的是()A.投资者作为注册资本投入企业的资金
有关片剂质量要求的正确叙述是A:溶出度不作要求 B:生物利用度比胶囊剂高 C
下列表述中不属于课外辅导的作用的是()。A.做好学生的思想工作 B.帮助学习
有关工程开工,下列说法正确的是()。A.监理人应在开工日期14天前向承包人发
履带式起重机属于()起重机的一种。A.桅杆式 B.塔式 C.自行杆式 D
最新回复
(
0
)