GWD-10--Q14

easylau

Yeasts capable of leavening bread are widespread, and in the many centuries during which the

ancient Egyptians made only unleavened bread, such yeasts must frequently have been mixed into

bread doughs accidentally. The Egyptians, however, did not discover leavened bread until about

3000 B.C. That discovery roughly coincided with the introduction of a wheat variety that was

preferable to previous varieties because its edible kernel could be removed from the husk without

first toasting the grain.

 

 

Which of the following, if true, provide the strongest evidence that the two developments were

causally related?

 

 

1. Even after the ancient Egyptians discovered leavened bread and the techniques for reliably
2. producing it were well known, unleavened bread continued to be widely consumed.
3. Only when the Egyptians stopped the practice of toasting grain were their stone-lined grain-toasting pits available for baking bread.

4. Heating a wheat kernel destroys its gluten, a protein that must be present in order for yeast to leaven bread dough.

5. The new variety of wheat, which had a more delicate flavor because it was not toasted, was reserved for the consumption of high officials when it first began to be grown.
6. Because the husk of the new variety of wheat was more easily removed, flour made from it required less effort to produce

答案是C，这题我做的时候就看的云里雾里的，还是不太明白，谁能给解释一下？

[此贴子已经被作者于2007-7-21 15:11:57编辑过]

addy

大家都知道Y能用来发酵面包,但是有很多个世纪埃及人都只会制作不发酵的面包(估计是一块实实在在的饼吧orz),而Y其实经常偶然地被埃及人混进面包团里去了(但是他们还是不会发酵面包orz).直到有一天,有一种新的小麦出现了,埃及人都很喜欢用它,因为不用烤它就可以直接把kernel从它的壳中分离出来了,而这个时候,埃及人知道了发酵面包.问题:怎么证明埃及人学会发酵面包跟这个小麦新品种出现有因果关系?

搭个桥:烤小麦会破坏它的gluten,这个东东是种蛋白质,生面团里必须有这个东东,Y才能发挥它的发酵作用

easylau

sigh，用中文解释了一遍就恍然大悟了～～～谢谢

alex31425

good

lenovoo

thx