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
A scientific discovery is often made 【C1】______ before someone is able to put it to use. 【C2】______ , scientists discovered how
A scientific discovery is often made 【C1】______ before someone is able to put it to use. 【C2】______ , scientists discovered how
admin
2010-03-19
60
问题
A scientific discovery is often made 【C1】______ before someone is able to put it to use. 【C2】______ , scientists discovered how to split atoms decades 【C3】______ the invention of the atomic bomb and the use of 【C4】______ power to produce electricity. But sometimes discovery and 【C5】______ happen at the same time, as occurred more than thirty years ago 【C6】______ the discovery of coherent light and the invention of the laser.
The word laser 【C7】______ "light amplification by stimulated emission of radiation." To many people, lasers are very mysterious, but a laser is simply a 【C8】______ that produces a strong light. The light from the laser is called 【C9】______ light because it is light that only moves in one direction. 【C10】______ , incoherent light, like the light from the sun or light from a bulb, moves away from its source 【C11】______ all directions, so its strength is very spread out. The light from a laser, moving in only one direction and 【C12】______ in a narrow beam, is much stronger. Laser light is created by a 【C13】______ called stimulated emission. In this process, the atoms of a certain substance, such as a crystal or a gas, are excited 【C14】______ that they produce coherent light. A person working with a laser can aim this coherent light, 【C15】______ a laser beam, in any direction.
As soon as the laser was developed, scientists began thinking of practical applications 【C16】______ it. One of the earliest uses was to make extremely precise measurements of distance and speed. 【C17】______ , the distance to the moon was measured to within a foot, and the speed of light was measured to 【C18】______ a thousandth of a mile per second. As time 【C19】______ , many more applications for the laser were 【C20】______ .
【C19】
选项
A、passing
B、passed
C、has passed
D、had passed
答案
B
解析
此题考查的是“随着时间的推移”英文的固定说法。该表达是as time passes(by)。我们还要注意到后半句中用了were,就表示前面也要用过去式。因此正确答案为B项passed。
转载请注明原文地址:https://kaotiyun.com/show/1Z9K777K
0
专业英语四级
相关试题推荐
Theearningsofwomenarewellbelowthatofmen______educationaldifferencesthatarediminishingbetweenthetwosexes.
Clothesplayacriticalpartintheconclusionswereachbyprovidingcluestowhopeopleare,whotheyarenot,andwhotheywo
OncefoundalmostentirelyinthewesternUnitedStatesandillAsia,dinosaurfossilsarenowbeingdiscoveredonallsevencon
Whataretheymainlytalkingabout?
Betweengettingupandhermeeting,thewomanhadabout______.
Manyayoungpersontellsmehewantstobeawriter.Ialwaysencouragesuchpeople,butIalsoexplainthatthere’sabigdiff
Shynessisthecauseofmuchunhappinessforagreatmanypeople.Shypeopleareanxiousandself-conscious;thatis,theyaree
Inanattempttogettothe_______oftheproblem,thereporterinterviewedeveryeyewitness.
Insomecountries,______iscalledequalitydoesnotreallymeanequalrightsforallpeople.
Hislittlefingerhasbecomeswollenduetothesnakebite.Hecanfeelit______withpain.
随机试题
二十国集团领导人同意为国际货币基金组织和世界银行等多边金融机构提供总额1万亿美元资金,使国际货币基金组织资金规模扩大至现在的3倍,以帮助受金融危机影响陷入困境的国家。最适合做这段文字标题的是()。
非职位权力包括()
某家具厂向某木材供应站订购了一批木材。但约定的交货日期到来时,木材供应站未能按期交货。两天后,因该地区遭遇罕见山洪,木材供应站所储存的全部木材被山洪冲走。家具厂因此停工待料10天,造成损失5万元。对家具厂的损失,应由谁承担?
内幕信息包括( )。
自尊(self-esteem)是社会工作实务中一个非常重要的概念,社会工作者经常把它运用于了解他人的内在世界。()
专门机关与广大群众相结合的方针,是指导公安机关和人民群众各项活动的基本方针。()
阅读下面的文章,回答问题。网络时代巨大的信息量要求网络人际交流迅速快捷,此时,传统语言的表达已不足以将信息转变成最简洁的形式输入输出。于是网络语言应运而生。这种语言以轻松活泼、幽默风趣、戏谑调侃的面目出没于传统媒体,让人耳目一新。比如“美眉”指年
A、 B、 C、 D、 A
InthemorningBernardwaspaleandhishandtrembledtoomucheventolifthiscoffeecup,______butterhistoast.
A、Taketheteno’clockbus.B、Comebackinfiveminutes.C、GotoNewYorkanotherday.D、Calltheairport.A
最新回复
(
0
)