GWD第七套 No.40

GWD-9-Q40:

Agricultural societies cannot exist without staple crops. Several food plants, such as kola and okra, are known to have been domesticated in western Africa, but they are all supplemental, not staple, foods. All the recorded staple crops grown in western Africa were introduced from elsewhere, beginning, at some unknown date, with rice and yams. Therefore, discovering when rice and yams were introduced into western Africa would establish the earliest date at which agricultural societies could have arisen there.

Which of the following is an assumption on which the argument depends?

1. People in western Africa did not develop staple crops that they stopped cultivating once rice and yams were introduced.

2. There are no plants native to western Africa that, if domesticated, could serve as staple food crops.

3. Rice and yams were grown as staple crops by the earliest agricultural societies outside of western Africa.

4. Kola and okra are better suited to growing conditions in western Africa than domesticated rice and yams are.

5. Kola and okra were domesticated in western Africa before rice and yams were introduced there.

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正确答案为A，个人认为B也对，因为如果有本土长成的主食的话，就不可能通过判断大米的种植时间而知道社会建立的时间了，各位的看法呢？

选A

B很混淆

题目说，recorded的rice and yams  from elsewhere 才可以算是这个国家农业社会的开端，

他的态度是说，原来国内即使有某些staple crops也不成功，也不算开端，而非要从recorded的rice and yams  from elsewhere 才可以算是这个国家农业社会的开端，

所以原来国家可以有staple crop没有关系，只要当rice and yams  from elsewhere 引进的那一刻开始，国内的staple不再耕种就可以了，否则就混淆了时间记载了。