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
2024-11-01
8
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] 【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://tihaiku.com/zcyy/3826503.html
相关试题推荐
"let’stakeawalkbeforewestarttostudy.""Oh,Ithinkit’s_______forwalki
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
Ascientificdiscoveryisoftenmade【C1】______beforesomeoneisabletopu
随机试题
[audioFiles]audio_eusm_j98_001(20082)[/audioFiles]A、Don’tgivetwo-monthrenti
Scienceisgenerallytakenasmeaningeither(a)theexactsciences,suchas
关于氨苄西林的特点,描述错误的是:()A.对G菌有较强抗菌作用 B.耐
我国发病率居第一位的恶性肿瘤为A.胃癌 B.肺癌 C.乳腺癌 D.结直肠癌
大体积混凝土施工应选用下列中的哪种水泥? A.硅酸盐水泥B.矿渣水泥C.铝
A.简单香豆素B.呋喃香豆素C.生物碱D.黄酮苷E.联苯环辛烯型木脂素秦皮中主要
中药调配时,每一剂的重量误差应控制在A.±1%以内 B.±2%以内 C.
甲不慎丢失贵重首饰后,在媒体上发布悬赏广告,称“若有归还者,给付酬金1000元”
道路旅客运输合同成立的时间以()为准。A:旅客开始上车 B:班车开始营运 C
( )是从BOT方式演变而来的一种新型方式,具体是指用民营资金购买某个项目资产
最新回复
(
0
)