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
2023-11-14
24
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 ascientific 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 them 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 thousand fold. [br] 【C20】
选项
A、perception
B、experience
C、reception
D、experiment
答案
A
解析
B:经验、体验;C:接待、接纳;D:实验、试验。只有A“感觉、感知”符合句意。
转载请注明原文地址:https://tihaiku.com/zcyy/3185017.html
相关试题推荐
Childrencanusuallydress_____bytheageoffive.A、themselvesB、themC、selvesD
Employeesshould______themselvesoftheopportunitytobuycheapsharesinthec
Allofthetouristswouldhaveenjoyedthemselvesmoreifthere______offersfo
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
随机试题
Itwasaboldideatobuildapowerstationinthedeepvalley,butit______as
Thecrisishas【C1】______questionsaboutthelargeoilcompaniesandwin
Weoftenadvisehimnottodrinkmorewine______isgoodforhishealth.A、asB、th
某项工程建设项目,业主与施工单位按《建设工程施工合同文本》签订了工程施工合同,工
奥运比赛组委会对各国运动员的尿样进行兴奋剂检查,应采用何种防腐剂保存尿样标本A.
患者,女性,39岁,1-0-2-1。因"痛经10年,加剧伴性交痛2年"就诊。若患
A.麻黄B.蜜麻黄C.麻黄绒D.蜜炙麻黄绒E.麻黄根风寒表实证宜选用的炮制规格是
Thechangeinthatvillagewasmiraculou
线性范围是指A.检测限B.定量限C.药物中杂质的检查D.制剂的含量表示方法E.定
施工总成本目标确定之后,还需通过编制详细的实施性施工成本计划把目标成本层层分解,
最新回复
(
0
)