56 Gold
It is only shiny, yellow metal, but it is one of the most valuable metals on the earth. Since the beginning of time, men have looked for this extremely valuable item, gold.
Gold is soft and easy to form into different objects．If it gets wet, it does not rust like iron or other metals．Acids do not change it．One important reason that gold is so valuable is that it is scarce．
Because of its softness，gold must be combined with other metals to harden it and give it strength．
By hardening gold，people can then make coins and jew-e1ry with it．Metals commonly mixed with gold are nickel，platinum，and copper. Gold jewelry bears a number and the letter K．The K means karat（carat)，which is a measure of the amount of pure gold in the jewelry．Pure gold is 24K．Therefore，a necklace which is 14K is fourteen parts gold and ten parts other metal．
金子
它仅仅是一块发光的黄色金属，但却是世界上最值钱的金属之一。从一开始，人们就在寻找这极有价值的东西—黄金。
金子很软而且容易被打造成不同的物品。即使它受潮了，它也不会像铁或其他金属那样生锈。酸也无法侵蚀它。金子为什么如此值钱的一个重要原因就是因为金子非常稀少。
因为金子的柔软，它就必须和其他金属掺在一块儿，以使它变得坚硬有力。
金子被加硬后，人们就可以用它打造硬币和珠宝。通常与金混合的金属有镍，铂和铜。金制的珠宝与一个数字和字母K有关。K就是克拉，它是纯金珠宝计量单位。纯金是24K。所以，一个14K的项链就是其中有14份是金子，另外10份是其他的金属。
词汇：
Shiny 有光泽的，发亮的 rust 锈
Scarce 缺乏的 combine 使结合
Harden 使坚固 nickel 镍
Platinum 白金，铂 pure 纯的，清洁的
I．听全文录音，选择正确答案
1. Gold is .
A. shiny, brown metal B. as valuable as diamonds
C. a hard metal D. easy to form into different objects
2 ．Gold is commonly mixed with ．
A ．nickel，platinum and silver
B ．nickel，copper and iron
C ．nickel，platinum and copper
D ．silver，copper and platinum
3.A ring which is 18k is .
A. 24 parts gold and 18 parts other metal
B. 18 parts gold and 6 parts other metal
C. 18 parts geld and 24 parts other metal
D ．6 parts gold and 18 parts other metal
II. 听录音, 补全下列段落
Gold is 1 and easy to form into different 2 .If it gets 3 , it does not 4 like 5 or other metals. 6 Do not change it. One important reason that gold is so valuable is that it is 7 .
Because of its 8 , gold must be combined with other metals to 9 it and give it 10 ．
答案:
I．1.D 2．C 3．B
II. 1.soft 2.objects 3. wet 4. rust 5．iron
6. Acids 7．scarce 8．softness 9. harden 10．strength
