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
2024-10-24
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 all 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】______ he 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] 【C13】
选项
A、though
B、as
C、than
D、and
答案
B
解析
要表示倒装和让步,只有B。
转载请注明原文地址:https://tihaiku.com/zcyy/3815911.html
相关试题推荐
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
Humansareuniqueintheextenttowhichtheycanreflectonthemselvesand
随机试题
Statusesaremarveloushumaninventionsthatenableustogetalongwithone
FinancialmattersFeesSpecialfeesarepaya
[originaltext]M:Goodmorning,love.W:Morning.M:Sleepwell?I’vemadesome
乳糜泻病人与下列哪种HLA抗原呈关联A.HLA-B17 B.HLA-DR3
工商行政管理部门依法行使前款规定的职权时,当事人应当予以协助、配合,不得拒绝、阻
某大桥桥宽26m,与路基同宽。桥长1216m,两岸各接线500m,地势较为平坦(
患者,男,45岁,间断上腹痛3年,加重2个月,胃镜检查发现胃角切迹溃疡,幽门螺杆
中国共产党第十七次全国代表大会报告对全面建设小康社会奋斗目标提出了新的更高要求。
委托人提供的会计报表严重失实,且被审计单位拒绝调整,此时,注册会计师应出具()的
女职工甲与某公司依法签订了无固定期限劳动合同。2017年7月,甲怀孕了,由于年龄
最新回复
(
0
)