首页
登录
职称英语
[img]2016m12s/ct_eyyjscz2015j_eyyjsccloze_0151_201611[/img] Diamond is the h
[img]2016m12s/ct_eyyjscz2015j_eyyjsccloze_0151_201611[/img] Diamond is the h
游客
2024-08-15
6
管理
问题
Diamond is the hardest naturally occurring substance known. It is the most popular gemstone and because of its extreme 【C1】______(hard), it is also used for various industrial purposes. Scientists are still 【C2】______(sure)of the exact process by which diamonds are naturally formed, but it is certain that both extreme heat and enormous pressure are needed. It is, therefore, likely that diamonds were formed far【C3】be______the Earth’s surface where these conditions exist. The first synthetic diamonds were successfully produced in the 1950s, but the best and largest stones are still those created by nature.
The word ’ diamond’ comes from the Greek ’ adamas’ , which means invincible, but the first definite reference to diamonds occurs in Roman literature of the first century A. D. The diamonds known to the Romans came from India, which was the only 【C4】______(supply)of the stones until the eighteenth century. In 1762, diamonds were discovered in Brazil, and then in 1866 in South Africa, the main source of diamonds in the world today.
The idea that men should give diamonds to the women they 【C5】______is quite new. It was invented in the last century by De Beers, the company that owns the South African diamond mines. The idea that ’diamonds are forever’ does not hold water either. Although diamonds are very hard, they can be【C6】dam______.
The largest of all known diamonds was the Cullinan. It was【C7】disc______in South Africa in 1905 and given to Edward VII, king of Great Britain. It was cut into smaller stones, the largest of which—and still the largest cut diamond in 【C8】______(exist)—is called the Star of Africa.
There have been a lot of diamond thefts in recent years, but scientists can now mark stones to show who own them. Usually this mark is 【C9】______(visible), so thieves can’t tell if a diamond is marked. 【C10】O______the people who know how to make the mark appear can tell whether a diamond is marked or not. [br] 【C1】
选项
答案
hardness
解析
(该句的意思是“钻石是世界上最受欢迎的宝石,因为它的高硬度”,根据所给的词hard可知,该处应填其名词形式hardness,表示“硬度”。)
转载请注明原文地址:https://tihaiku.com/zcyy/3720410.html
相关试题推荐
[img]2016m12s/ct_eyyjscz2016j_eyyjsccloze_0121_201611[/img]Modernsocietye
[img]2016m12s/ct_eyyjscz2016j_eyyjsccloze_0121_201611[/img]Modernsocietye
[img]2016m12s/ct_eyyjscz2016j_eyyjsccloze_0121_201611[/img]Modernsocietye
[img]2016m12s/ct_eyyjscz2016j_eyyjsccloze_0121_201611[/img]Modernsocietye
[img]2016m12s/ct_eyyjscz2016j_eyyjsccloze_0121_201611[/img]Modernsocietye
Whatarethemissingnumbersinthelastdiamondinthesequencebelow?[img]201
[img]2016m12s/ct_eyyjscz2016j_eyyjscreadd_0150_201611[/img]Likepeople,eac
[img]2016m12s/ct_eyyjscz2016j_eyyjscreadd_0150_201611[/img]Likepeople,eac
[img]2016m12s/ct_eyyjscz2016j_eyyjscreadd_0150_201611[/img]Likepeople,eac
[img]2019m5x/ct_eyyjscz2018j_eyyjsccloze_0048_201904[/img]Scientistsarepa
随机试题
[originaltext]W:Idon’tunderstandwhyIreceivedsuchalowgradeonmymath
Writeanessaybasedonthefollowingchart.Summarizetheinformationandrepor
下列关于建筑设计抗震概念的相关论述,哪项不正确?( )A.建筑设计应符合抗震概
某在用普通钢筋混凝土简支梁桥,截面构造为单箱单室,现需对该桥进行实际承载力的检测
复式教学是一种()。A.教学指导思想 B.教学基本原则 C.教学基本方
在2009年的资金来源中,个人按揭贷款比国内贷款低()个百分点。A.3.
领导替代论中提到,领导者并不总是对下属产生影响,因为对个体工作绩效和工作满意度产
呼吸性酸中毒合并代谢性碱中毒的血气改变特点不包括( )。A.PaCO2增高
牙折概述
环境污染的特点是() A.环境污染影响的范围广 B.对人群健康影响时间长
最新回复
(
0
)