美国科学60秒 SSS 2012-12-12(在线收听

 What prehistoric genius first discovered how to transform milk into delicious cheese? We may never find out, but we now know that humans were purposefully making cheese as early as 7,500 years ago. The finding is in the journal Nature. 

 
To make cheese, you first force milk to coagulate into curds. Then you strain off the liquid, called whey.
 
Modern cheese strainers bear a strong resemblance to the remains of 34 clay vessels recovered from Polish archaeological sites. But researchers did not know if the vessels might have also have served other purposes. The new study analyzed the residues on these unglazed pottery shards and found the remains of milk fat. Which proves that these containers were part of the cheese-making process more than 7,000 years ago.
 
Cheese was more than a tasty treat. These prehistoric humans were likely lactose intolerant, and had trouble digesting unprocessed milk. By straining out the lactose-rich whey and transforming the milk solids into cheese, dairy farmers gained nutrition from cows without slaughtering their food source. And finally discovered what to put on crackers.
  原文地址:http://www.tingroom.com/lesson/sasss/2012/12/216884.html