首页
登录
职称英语
Trillions of incredibly tiny diamonds, possibly formed by a dying star befo
Trillions of incredibly tiny diamonds, possibly formed by a dying star befo
游客
2023-11-18
67
管理
问题
Trillions of incredibly tiny diamonds, possibly formed by a dying star before the solar system was born 4.5 billion years ago, have been found by researchers 【C1】______ four meteorites.
The powder-like diamonds could be among the oldest things in the 【C2】______ , said Roy Lewis, senior research associate at the University of Chicago.
The diamonds may 【C3】______ clues about the chemistry of stars, and if scientists can determine how they formed, that could suggest better ways of manufacturing tiny diamonds for 【C4】______ purposes, he said.
"It’s quite possible that nature is doing it more 【C5】______ than we’ve been doing it," he said. "So maybe we’ve got something to learn."
The new find is 【C6】______ , said John Wood, staff scientist at the Harvard-Smithsonian Centre for Astrophysics. Although diamonds have been found before in meteorites, they were formed relatively recently 【C7】______ the shock of impact, he said in a telephone interview.
But Wood said the new report made him "quite sure" the newly found diamonds are older than the sun.
Lewis said researchers never expected to find diamonds when they started 【C8】______ a stone-like meteorite that had plunged into Mexican cornfield in 1969.
They were studying an unusual carbon dust in the meteorite, and to purify the sample they went though several steps to dissolve other materials. They expected the sample to remain black through the purification, but to their surprise in the final step it turned 【C9】______ .
Lewis said they believed the final stage had dissolved the carbon they wanted to study. But tests showed that the white residue was in fact made of carbon. Other tests found that it contained an unusual combination of forms of the gas xenon, 【C10】______ that it came from outside the solar system.
Still another battery of tests 【C11】______ the residue as diamond dust, so fine that a row of 20,000 grains would extend about the 【C12】______ of a human hair.
The researchers also found diamonds in three other meteorites, Lewis said. Tests showed all four meteorites were as old as the solar system, and that the embedded diamonds did not form within the meteorite 【C13】______ of collisions.
So the diamonds must have 【C14】______ somewhere else before the meteorites formed, making them as old or older than the solar system.
The diamonds may have formed in the upper atmosphere of a star in the late "red giant" stage, where the temperature and abundance of hydrogen could 【C15】______ diamonds to form as carbon gas condenses. [br] 【C8】
选项
A、engage in
B、study
C、inquiring
D、investigating
答案
D
解析
start doing sth.“开始做某事”,investigate意为“调查”。
转载请注明原文地址:https://tihaiku.com/zcyy/3199052.html
相关试题推荐
Inaphysicalchangenonewsubstanceisformed,______inthecompositionofmat
Theenergy______bythechainreactionistransformedintoheat.A、entrustedB、r
Peopleunderstresshaveperformed______featsofstrength,likeliftinganaut
Trillionsofincrediblytinydiamonds,possiblyformedbyadyingstarbefo
Trillionsofincrediblytinydiamonds,possiblyformedbyadyingstarbefo
Trillionsofincrediblytinydiamonds,possiblyformedbyadyingstarbefo
Trillionsofincrediblytinydiamonds,possiblyformedbyadyingstarbefo
Trillionsofincrediblytinydiamonds,possiblyformedbyadyingstarbefo
Trillionsofincrediblytinydiamonds,possiblyformedbyadyingstarbefo
Trillionsofincrediblytinydiamonds,possiblyformedbyadyingstarbefo
随机试题
Changesinthetechnologyofcommunicationareoccurringsorapidlythatwe
[originaltext]MymotherwasborninasmalltowninnorthernItaly.[16]She
请回答有关路基路面几何尺寸测试方法的问题。(4)路基边坡坡度测试方法有()
某省民政厅为了制定本省医疗改革方案,需要对本省的医疗机构和就医人员情况进行调查。
《招标投标法实施条例》规定,招标人发售资格预审文件、招标文件收取的费用应当包括(
脐中至横骨上廉(耻骨联合上缘)的骨度分寸是( )。A.13寸 B.12寸
凡妊娠12周内,胚胎自然殒堕者,称为A.滑胎 B.堕胎 C.小产 D.胎动
药敏试验时无须加入补充物质的细菌是A、流感嗜血杆菌B、淋病奈瑟菌C、脑膜炎奈
黄女士于2010年4月30日在某股份制银行申购了甲基金公司的某款基金,下列关于该
某小型排涝枢纽工程,由排涝泵站、自排涵闸和支沟口主河道堤防等建筑物组成。泵站和自
最新回复
(
0
)