gwd 31中1

sfj212

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, provides the strongest evidence that the two developments were causally related?(两者发展是因果关系)

 

1. Even after the ancient Egyptians discovered leavened bread and the techniques for reliably producing it were well known, unleavened bread continued to be widely consumed.

2. Only when the Egyptians stopped the practice of toasting grain were their stone-lined grain-toasting pits available for baking bread.

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

4. The new variety of wheat, which had a more delicate flavor风味 because it was not toasted, was reserved for the consumption of high officials when it first began to be grown.没有说两者的联系

5. Because the husk of the new variety of wheat was more easily removed, flour made from it required less effort to produce.文章中没有比较  

                      Answer:C

不知道分析的对不对，还不是很理解到底是什么样的关系，哪位高手指点下啊

pdsb

两个developments是1.埃及人用酵母做发面面包
                  2.埃及人引进了新品种的小麦，这种小麦不需要加热就可以脱壳。


c项说    加热小麦仁会破坏一种成分g，而这种成分是酵母发面所必须的。

因为要做面包首先要把小麦脱壳，而老品种的小麦脱壳必须先加热，就破坏了那种成分g。  导致没法用酵母做发面面包。

所以只有引进了新品种之后，才可以发面成功。  有了development2才导致了development1。

 这就是两个developments相关的证据