首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
【C1】______ nearly a hundred years of powered flight, scientists are still trying to figure out how birds fly. Researchers have
【C1】______ nearly a hundred years of powered flight, scientists are still trying to figure out how birds fly. Researchers have
admin
2010-01-10
50
问题
【C1】______ nearly a hundred years of powered flight, scientists are still trying to figure out how birds fly.
Researchers have learned that the slapping noise pigeons make when they suddenly take off is the sound of super charged lift. They call it the "clap fling" effect.
Here at SRI International scientists try to duplicate the pigeons’ thrust. A flashing strobe reveals the secret.
Scott Stanford, a scientist at SRI, says, You re looking at the clap fling effect, where the two wings will come together and peel apart 【C2】______ each other, thus augmenting lift 【C3】______ drawing air from the top to the bottom. "
This mechanical bug won’t get off the ground. 【C4】______ its flapping wings demonstrate a potential propulsion system for robotic birds: man-made rubbery muscle.
Roy Kornbluh works at SRI. "There, I’m turning the voltage on and off, and you can see when the voltage is on, the material is larger 【C5】______ when the voltage is off."
Super computers show high-speed airflows over supersonic aircraft.
But scientists have only begun to see how air flows 【C6】______ really low speeds.
Professor Max Platzer of the Naval Postgraduate School, says, "The flapping wing is generating a thrust, this way, this is the basic physics of the phenomenon."
It’s pelicans--not pigeons--the Navy is looking at. The Navy is looking at the smooth easy flight of pelicans low over water--called "ground effect." Researchers at the Naval Postgraduate School are trying to imitate the pelican’s efficiency.
Assistant Professor Kevin Jones of the Naval Postgraduate School says, " 【C7】______ flapping the wings, symmetrically, we’re 【C8】______ effect imitating ground effect. We now have the same feature a bird sees when it’s flying, over a ground plane."
An electric motor drives the flapping wings. Researchers here are working 【C9】______ ways to beam power to the tiny bird.
David Jenn of the Naval Postgraduate School says, "There’s no battery inside of here, so we’re going to set this inside the radar beam, and the energy is extracted from the radar beam and will be used to propel the motor."
Scientists are learning it’s one thing to build an airplane, 【C10】______ quite another to build a bird.
【C1】______
选项
答案
After
解析
转载请注明原文地址:https://kaotiyun.com/show/eDKd777K
本试题收录于:
BEC高级阅读题库BEC商务英语分类
0
BEC高级阅读
BEC商务英语
相关试题推荐
Whatisthewomanbuying?
A、 B、 C、 D、 BTheequipment,theuniforms,andtheenvironmentsuggestscientistsinalaboratory.Choice
A、 B、 C、 AThreehundredthousanddollarsanswershowmuchmoney.Choice(B)repeatsmanyofthewordsusedint
Whattypeofbusinessisthemancalling?
WhatdoesthewomanmentionaboutNationwideCable?
Iscorporatephilanthropyimportantornot?Canyougiveexplanationsforcorporatephilanthropy?
Askingforexplanations要求说明
•Youwillhearabusinesspresentationabout3simplesellingtactics.•Asyoulisten,forquestions1—12,completethenotes,
•Youwillhearabusinesspresentationabout3simplesellingtactics.•Asyoulisten,forquestions1—-12,completethenotes,
•Youwillhearabusinesspresentationabout3simplesellingtactics.•Asyoulisten,forquestions1—-12,completethenotes,
随机试题
女,44岁,拇指掌面基底部疼痛及弹响1年,加重2周。体格检查:该部位可扪及一小结节,有压痛,伸屈拇指时可感到弹响,最可能的诊断是
男,60岁,咳嗽,右胸痛,2个月憋气,抽烟30年,20支/日。胸片示,右肺门增大,右侧胸腔积液,拟诊断为右肺癌,胸膜转移。下列哪项检查有确诊价值
A.镇惊安神B.解郁安神C.养心安神D.清心安神E.健脾安神夜交藤的功效是
由于基础货币能为金融当局所直接控制,在()不变的条件下,金融当局即可通过控制基础货币来控制整个货币供给量。
下列要素中,不属于意外伤害保险中伤害构成要素的是()。
根据证券法律制度的规定,下列关于证券发行程序的表述正确的是()。
国外最早的教育学著作是()。
______YellowRiveristhesecondbiggestriverinChina.
SalariedContractDr.Balignant,MD,FRCPC,SpecialistOfferedfromSaintLewi
Ilovetravelingbytrain.Fast【B1】______,slowlocaltrainswhichstopateverystation,【B2】______trainstakingbusinessmento
最新回复
(
0
)