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06-A. Diamonds

Published:2013-01-19 16:22 Click:wait for……
06-A. Diamonds Diamonds are rare, beautiful, and also quite useful. They are the hardest substance found in nature. That means a diamond can cut any other surface. And only another diamond can make a slight cut in a diamond. Diamonds are ma
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06-A. Diamonds
Diamonds are rare, beautiful, and also quite useful. They are the hardest substance found in nature. That means a diamond can cut any other surface. And only another diamond can make a slight cut in a diamond.
Diamonds are made from carbon. Carbon is found in all living things, both plant and animal. Much of the carbon in the earth comes from things that once lived.
Scientists know that the combination of extreme heat and pressure changes carbon into diamonds. Such heat and pressure exist only in the hot, liquid mass of molten rock deep inside the earth. It is thought that millions of years ago this liquid mass pushed upward through cracks in the earth’s crust. As the liquid cooled, the carbon changed into diamond crystals.
There are only four areas where very many diamonds have been found.
The first known area was in India, where diamonds were found thousands of years ago. In the 1600’s, travelers from Europe brought back these beautiful stones from India. Diamonds became very popular with the kings and queens of Europe.
In the 1720’s, diamonds were discovered in Brazil. This discovery came at a good time, too. India’s supply of diamonds was finally running out after 2,500 years of mining the stones.
In the 1800’s, two other important areas were found in Russia and South Africa. Today, most diamonds used in industry come from Russia. Most diamonds used as gems come from South Africa. Only 25 percent of all diamonds mined are good enough for cutting into gems.
Most of the diamonds in India were found in stream beds.  People would pick up handfuls of gravel from the bottom of the streams and sort out the diamonds. These diamonds were probably carried from where they were formed to India by great sheets of moving ice that covered parts of the earth 20,000 years ago.
Most diamonds today are not found in stream beds, however. They are mined from rock formations deep inside the earth called pipes. Scientists believe that these are parts of volcanoes that were formed when molten rock pushed upward through the earth’s crust. The hard rock in which diamonds are found is called blue ground, because it is somewhat blue. The blue ground is blasted into large pieces of rock which are carried to the surface by elevator. Then the rocks are carefully crushed so that the diamonds are not destroyed. Next, the crushed material is taken over to washing tables. Here, it flows over boards thickly coated with grease. Since diamonds stick to grease, they are left behind by the rocks and mud which flow down the tables.
Diamonds, as they are found, do not look very impressive. They are gray, greasy-looking pebbles. Experienced diamond miners can tell a diamond immediately. But some people have carried around an unusual pebble for weeks before finding out that they had got a diamond.
 

如果下面音标不能正确显示,请自行安装字体文件 TOPhonetic.ttf
 

rare[rA4]a. 稀有的,难得的
substance['s8bst4ns]n.1.物质;2.实质,本质;3.主旨,大意
slight[slait]a.轻微的,纤细的   

 carbon['k2:b4n]n.碳
extreme[iks'tri:m]a.1.极端的,极度的;2.尽头的,末端的;n.极端
pressure['pre54]n.压力,压强
liquid['likwid]a.液体的,液态的;n.液体
molten['m4ult4n]a.(melt的过去分词)(指金属)熔化的
crack[kr1k]n.裂缝,裂口;vi.爆裂,破裂
crust[kr8st]n. 1.地壳;2.面包皮,硬外皮,外壳
crystal['kristl]n.水晶;晶粒;a.清澈透明的,水晶制的,晶体的
popular['p3pjul4]a.流行的,通俗的,大众的;受欢迎的
gem[d9em]n.宝石,珠宝      

 handful['h1ndful]n.一把,一小撮
gravel['gr1v4l]n.碎石,砂砾
formation[f3:'mei54n]n.1.[地]岩层;2.形成,构成
pipe[paip]n.1.管子,导管;2.烟斗;3.火山筒;vt.用管道输送
volcano[v3l'kein4u]n.火山       

somewhat['s8mw3t]ad.稍微,有点
blast[bl2:st]n.1.疾风,强风;2.爆炸;vt.炸,炸掉
elevator['eliveit4]n.电梯,升降机
crush[kr85]vt.1.压碎,碾碎;2.镇压,压倒
destroy[dis'tr3i]vt.1.破坏,毁灭;2.消灭
grease[gri:s]n.油脂;滑脂
impressive[im'presiv]a.给人印象深刻的,感人的
greasy['gri:zi]a.1.涂有油脂的,油污的;2.油腻的,滑的
pebble['pebl]n.小圆石;卵石
experienced[iks'pi4ri4nsd]a.有经验的
miner['main4]n.矿工       

immediately[i'mi:dj4tli]ad.1.立即地,即刻地;2.直接地,紧密地
be made of由...构成        

be popular with受...喜欢;受...欢迎
run out用尽       

sort out分类,整理       
stick to附着,粘住
 
 
 

Unit 6 Text ADiamonds
搭配:
1. change sth. into sth.  把什么变成什么/动词词组
2. exist in  存在于/动词词组
3. mass of  团、堆、块/表量词组
4. become popular with/among sb.  受谁的喜欢,欢迎/动词词组
5. come at a good time  适逢其时/动词词组
6. be running out  渐渐用尽/动词词组
7. handfuls of  成捧的(东西)/表量词组
8. sort out  淘选出/动词词组
语言点:
1. be made from sth.指sth.已看不出原材料(如酒是高粱做的);be make of sth. 指sth.可以看出原材料(如桌子是木头做的)
2. it is thought that +从句  人们认为
3. good enough for doing sth.  好到可以做某事
4. experience(n./v.)-experienced(adj.有经验的)
5. be classed as  被作为什么而分类/动词词组
6. the former…the latter  前者,后者
Unit Six

1. In the 1600's , travelers from Europe _______(bring) back diamonds from India. (00.4)

  答案为brought 。考点是一般过去时,bring 是不规则动词,过去式是brought.
2. There are only four areas ______ very many diamonds have been found. (02.10)

  A. when B. where C. that D. which
  答案为B。考点是定语从句。先行词为areas,因此用where 引导定语从句。
3. In the 1720's , diamonds _______(discover) in Brazil. (02.10)
  答案为were discovered。考点是一般过去式的被动式,因为In the 1720's 是明显的过去时的时间状语。4. The real difference between plants and animals ______ in what they do , and not in what they seem to be. (01.10)
  A. is laid B. is lain C. lays D. lies
  答案是D 考点是lie in 在于。Lie 的词型变化为 lie , lay , lain
5. We now know that about ______ all the kinds of seaweed are animals. (01.10)

  A. one fourth B. one fourth of C. one four of D. the one fourth
  答案为B 考点是四分之一的表达,并且根据本句的意思还要加上所属格of .此句的意思为"我们现在知道了在各种海草中约有四分之一是动物。
6. Animals can live only on ______ plants have already turned form inorganic to vegetable matter. (01.10)
  A. that B. which C. what D. how
  答案是C . 此句的意思是动物只能靠植物将无机物转换成植物性物质来生活。What 引导宾语从句做on 的介词宾语。
7. The first ______(know) area was in India, where diamonds were found thousands of years ago. 01.10
  答案是known 考点是过去分词做定语。

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