首页
登录
职称英语
A scientific discovery is often made【C1】______ before someone is able to pu
A scientific discovery is often made【C1】______ before someone is able to pu
游客
2023-11-23
50
管理
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】______ . [br] 【C12】
选项
A、concentrated
B、concentrating
C、concentration
D、concentrate
答案
A
解析
此题考查非谓语动词的用法。这里我们要看主语the light from a laser和动词concentrate之间的关系是被动还是主动:主动用-ing形式,而被动则用-ed形式。该句中为被动,所以正确答案为A项concentrated。
转载请注明原文地址:https://tihaiku.com/zcyy/3211928.html
相关试题推荐
Usually,therearetworeasonstopursuescientificknowledge:forthesakeof
Usually,therearetworeasonstopursuescientificknowledge:forthesakeof
Usually,therearetworeasonstopursuescientificknowledge:forthesakeof
Usually,therearetworeasonstopursuescientificknowledge:forthesakeof
Usually,therearetworeasonstopursuescientificknowledge:forthesakeof
ThescientificnameistheHoloceneAge,butclimatologistsliketocallour
ThescientificnameistheHoloceneAge,butclimatologistsliketocallour
ThescientificnameistheHoloceneAge,butclimatologistsliketocallour
PassageOne[br]WhatdoesthepartbeforethedashdescribeinPara.7?The
OnFeb.2,2007,theUnitedNationsscientificpanelstudyingclimatechang
随机试题
[originaltext](29)Somepeopledon’tlikeanythingtobeoutofplace.They
[originaltext]W:Hi,Jack.M:Hi,Jean.Iwasjustlookingforyou.W:What’su
有一个项目做得很成功,但是你没参与,领导却以为是你做的,你怎么办?
分批法以不同批别或订单的产品作为成本计算对象。()
地面面砖工程的施工质量控制点的预防措施中,施工前地面砖需要挑选,将颜色、花纹、(
维持子宫前倾主要的韧带是A、子宫阔韧带 B、子宫圆韧带 C、子宫主韧带 D
骨折刚达到临床愈合时,正处于骨折愈合过程的哪一阶段A.血肿机化演进期 B.骨折
工程总承包合同中的索赔包括()。A、承包人索赔的提出B、承包人索赔处理程序C
归脾汤中用木香的用意是A.补而不滞 B.理气疏肝 C.行气止痛 D.行气止
根据电子商务法基本制度的规定,下列关于电子商务合同的履行和快递物流的表述中,正确
最新回复
(
0
)